The question many are posing is: Has it gone too far?
Those who have spent their lives in the town - and have seen the changes - speak of "entire streets" which are now just holiday lets, the loss of community spirit, and an infrastructure at breaking point.
Many suspect the only way now, is down.
"For those who have lived here all their lives, what you can do has changed," explains Graham Cox, 69, of the Whitstable Society. "We knew in the 1980s we could do certain things in our home town on a Saturday - but 20 years later that had ended.
"It was too crowded, it was full of people who didn't relate to Whitstable, bringing down their unfriendly London habits, which we had not seen before. The old life had completely gone.
"It was sleepy, then it was known and developed, then it became over-crowded and now I think the interest is waning."
And he is not alone in his opinion.
Certainly the town has undergone a seismic shift over the last 25 years, with a number of key reasons cited for its transformation - with two or three key moves being seen as responsible; more on those later.
Colin Carmichael joined as chief executive of Canterbury City Council in 1996 - just before the town's popularity started to rocket.
He remembers: "It didn't have that thing about it when I first came to Canterbury. In fact it was on a list of faded fishing towns - in the same category as fishing villages in Cornwall, where the main industry was being depressed and there were not a huge amount of alternatives.
"One thing I do remember is we put in a bid to be the European Capital of Culture as Canterbury and East Kent around 2000.
"There was a visit from the judging panel and there were 12 people on it - they visited each of the cities for a day and we had to show them around. We had this grand plan to do a tour of Canterbury and then go out to tour Margate and show them where the Turner Contemporary was going to be built. And they hijacked it.
"They said they wanted to go to Whitstable. They said 'we've heard all about this amazing place and we want to go and see it'. We took them up there and they had a lovely time. They loved wandering around.
"But what was really interesting on the day, this group, led by Sir Jeremy Isaacs [most famous for being the founding chief executive of Channel 4], with journalists, TV presenters and other culture people, made the choice to go to Whitstable. For me that was a really telling moment."
It hasn't looked back since; a romance with the national media fuelling a relentless wave of day-trippers and holiday-makers.
But it wasn't always the way.
What, in the mid-1990s, was once a cheap alternative to nearby Canterbury - many homes on its main thoroughfare used as accommodation for students studying at the city's universities - has seen its property prices accelerate at break-neck speed. According to Rightmove, the average price of properties sold in the town is £417,935. To put that into context, that is an average price only eclipsed in the traditional commuter belt of west Kent.
While that may be good news for many looking to cash in on their new-found property wealth, it has, claim many, ushered in a new set of problems.
"Before," adds Mr Cox, "even in the middle of winter you had a reasonably lively social life going on in the centre of the town. But it's got to the point now, where in January and February, the centre of the town is depressed. And that's because so many houses are either holiday lets or second homes. None of those are visited during the winter and it deadens the place.
"So it switches from having a dead heart in the winter to being over-crowded by people who hardly know Whitstable in the summer and you can't move around. It's been changed very dramatically.
"I think there was a lack of protest in the centre of Whitstable because some of the long-standing residents made an absolute fortune from this. The impression I get from being on the planning committee of the Whitstable Society is that virtually every property two or three streets back from the beach have changed hands over the last 20 to 30 years."
Brian Hitcham is a well-known figure in the town. He has spent 60 fr his 65 years living there. He used to run a popular bookshop and was previously president of the town's chamber of commerce and a former chair of the trust which runs the local museum.
"The town's very DNA has changed," he believes. "People living here are less connected to the town and less concerned. The community spirit has diminished considerably.
"Locals don't want to go into town at the weekends or along the seafront anymore - it's not pleasant during the peak times. And first thing in the morning where you see all the rubbish and damage that's been done - that's not a positive experience."
Coupled with its popularity has come a rise in trouble on its streets. Its popular Oyster Festival - which at one stage sprawled over 10-days during the summer - had to be scaled back dramatically due to nuisance behaviour caused by drinking.
Anti-social behaviour has been fuelled by youngsters heading to its beaches - lured in by the headlines it generates, while litter left by visitors is a regular bug bear.
"In five to 10 years I think people will abandon it," warns Mr Hitcham. "More people who came here with their rose-tinted glasses, are now seeing a side you don't see when visiting and only becomes apparent when you've been here a while. And I think the quality of life is diminishing. It's a less rewarding place to live than it used to be. And I think that's very sad."
And he fears the town has not only reached the tipping point but has tumbled over the edge.
"The balance between pleasing the visitor and those who live here has gone totally," he says, "and I don't think it can be recovered."
It's hard to see the under-lying issues for the day-tripper. The town retains much of its charms, a bustling high street full of independent stores, boutiques, restaurants and cafés leading to a stretch of pebble beach dotted with pubs. Its harbour's gently bobbing boats are off-set by seafood stalls and the industry which continues to support it.
There's no seafront road, so the beach has the sea on one side - offering views across the gentle waters of the Thames Estuary to Sheppey - and pretty weather-boarded cottages on the other.
Even those long-term residents who have welcomed the changes believe the town is teetering on a precipice it can ill afford to fall into.
"I'm happy with how it's progressed," says David Roberts, 76, chair of the Whitstable Improvement Trust and trustee of the museum. "Tourism has regenerated the town.
"You look at old photographs and the exact same buildings are there in the high street - we've not destroyed our local architecture and that's a big plus.
"I think the balance is right - people will always moan because people leave litter, but that's not peculiar to Whitstable. That's a human disease. We just have to live with it and try and cope with it.
"I think it's a bit of an exaggeration to say there are streets full of holiday or second homes. The majority are still owned and inhabited by local people - they might have bought them and are commuting to London - but they become locals."
But he admits things have changed: "This is a bit of exaggeration, but everyone used to know everybody in Whitstable. It was a town full of families. We're losing that.
"I don't think it’s changed the DNA - but it's gradually changing it.
"Whitstable has gone as far as it can without being spoilt."
So just what happened to change Whitstable from forgotten fishing town to being dubbed Islington-on-Sea courtesy of the surge of London day-trippers?
Two factors were key.
First the dualling of the Thanet Way between the M2 and the town in 1989 made a significant difference - freeing up previously snarled up traffic during the peak months.
Explains Graham Cox: "I grew up in Seasalter and at weekends we couldn't hear the Thanet Way because it was stationary.
"People were put off coming here because they didn't want to sit in traffic jams, especially with the hoi polloi going down to Margate.
"You could actually detect the change by the number of high-end cars you could see. I had never seen one in the high street until this change began. Then, during the 1990s, slowly it started going up and up. By the Noughties it was just commonplace."
The other key factor - and perhaps equally significant - was promotion by the Greens; arguably the town's most influential - and controversial - family.
Barrie Green bought the rapidly sinking Whitstable Oyster Fishery Company in 1976 - by then a ghost of the industry in the shellfish with which the town is now synonymous. He purchased it with money raised from his chain of wallpaper and paint shops.
A few years later, spearheaded by his sons, Richard and James, it refurbished the main building and opened at first a tearooms, before turning it into what is today a celebrated fish restaurant and accommodation. By 1997 it had opened the Hotel Continental too.
"The Greens really carried out a heavy marketing exercise on their seafood restaurant," explains Brian Hitcham, "and they managed to get in with some of the national newspapers.
"Certainly, they made a major contribution towards it and to be fair they have been one of the major beneficiaries."
The Greens own various sites in the town as well as swathes of the beach - much to the on-going chagrin of many.
But James Green says the town was in need of what his company delivered.
"When my father bought the majority of shares in the company in 1976 it had one employee," he explains. "From a company which employed most of Whitstable and had 200 boats at the beginning of the 20th century to that was a pretty dramatic decline.
"The Oyster Company restaurant [the Royal Native Oyster Stores which butts into the beach] opened in about 1988 - originally as a tearoom and coffee shop which didn't attract a lot of attention. Then we changed it to a purely fish restaurant which at the time was very unusual. To have a purely fish restaurant by the sea was probably one of very few - the other was down at Padstow [in Cornwall] with Rick Stein.
"There was one particular article in The Times by Jonathan Meades in the early 1990s. It was the first we had. He did a full page which was pretty glowing and food-related and that was a turning point for us. All of a sudden we started to get people coming down from London.
"We had the media coming down on a pretty regular basis after that.
"Even though Whitstable is very nice, people still need a reason to go there - otherwise you're just wandering up and down the beach. To have a nice fish restaurant on the beach is what started to attract quite a lot of people."
James Green also points to the sea defences work in the mid to late 1980s - a move which achieved what King Canute was never able to do by keeping back the tide from lapping at the town's sea wall. It opened up the top of the beach at all times.
So how much of the credit does his family take for the town's transformation?
"I don't think we're solely responsible," he says, "but a large proportion is us. We were in the right place at the right time and we did something quite unusual to start off with.
"My brother and I were quite young - in our early 20s - and that was perhaps part of the attraction for people writing the articles too, maybe."
As the Sunday newspaper features started to generate interest, by 1999 the town's Oyster Festival was declared the year's third most-anticipated summer festival in the Independent - eclipsed only by Glastonbury and the Edinburgh Fringe Festival, while beating off the challenge of the likes of the Cannes Film Festival and the Notting Hill Carnival. High praise indeed.
"Whitstable's rise was a weird phenomenon," says Colin Carmichael, chief executive of Canterbury City Council.
He agrees the Greens' influence was significant in the town's revival. "They worked out they needed the Down from Londoners to come and they did very well at that.
"People with money from London or elsewhere have come for second homes or visit regularly. They like the quirkiness and everything that goes with it.
"The small shops, which are so popular in Whitstable, survive because people with money come and spend in those shops. It's like a positive circle."
But while the town has won plaudits for its diverse range of stores, there are worrying signs there too that its success is taking it down an irreversible path.
Adds Brian Hitcham, who ran Oxford Street Books for many years: "Shop rents, for a start, will make it very difficult for everyday retailers to survive. You have to have something with high margins - like food and drink - that's why we have so many restaurants and hairdressers because the margins are good enough to afford the rents. That's what has driven the rents up generally.
"People decide they want to open a new business here and can afford a certain amount for a building but have no understanding whatever rent they agree can impact directly on future rent increases for the rest of the town.
"So, when a butchers moved in and were desperate to get a foothold, they rented a tiny shop at an enormous price per square foot. It set the highest rate in the town by a long way. And then when the next rent review comes up for the next shop, it's then used as the going rate. That continues to happen even now."
And there are other issues too.
Adds the Whitstable Society's Graham Cox: "If I was sat down in front of a psychoanalyst and asked why I was depressed about Whitstable it is the vehicle pollution. If you go there on a busy day it is appalling in the high street and all those central places. You can taste it and smell it.
"There's a limitation on car parking, no park and ride so inevitably the point came when it began to be overcrowded.
"It wasn't just the queue going all the way out to the new Thanet Way of a Saturday morning, but even the width of the pavement - so down near Harbour Street the pavements are relatively narrow and then you get baby buggies in the highway and to me that is a sign of a problem.
"The town should be closed to visitors at the point vulnerable people are forced to walk in the street. It's getting crazy."
So what can be done? Perhaps not surprisingly, plenty of fingers of blame are pointed at Canterbury City Council. A regular refrain is that the authority overlooks the town - focusing instead on the cathedral city.
Graham Cox's views are echoed by many: "Not all changes are council directed, but they control the Local Plan and that controls a lot of things. Colin Carmichael once told us he wanted Whitstable to be like St Ives, but in doing that, the terrible infrastructural problems of St Ives he's visited on Whitstable.
"It's gone beyond its infrastructural capability and the council has done nothing to, fundamentally, address that. The park and ride is the classic; despite the best attempts they haven't done one, so everyone tries to jam in by car into the town. “
Adds David Roberts of the Whitstable Improvement Trust: "When it comes to Whitstable they [Canterbury City Council] tend to use the excuse - we know its popular we don't have to worry too much about it.
"There could be more investment and more understanding. Herne Bay has benefitted more than Whitstable in many respects.
"I understand the council has priorities. But I thnk it could value Whitstable more."
Colin Carmichael dismisses such speculation. He insists the council has deliberately taken a softly-softly approach to the town - and points out that problems with the roads is a matter for the county council.
"Whitstable needed tourism to replace its declining industries,” he explains. “I would love to say the council had a grand plan to do that, but I'd be fibbing.
"Once it started it's rise we tinkered with it. We stroked its fur and helped it as opposed to the council making it happen. As it developed our job was to help it along.
"I don't think the criticism aimed at us is justified.
"Sometimes people over-estimate what councils can and should do.
"If there were obvious things for us to do, we would do them. We keep the streets cleaned, we get the bins emptied, we get rid of the graffiti. When it's been our land we've used it to improve things.
"When an opportunity has come along to make improvements, we've done it. Inevitably what you do as a council will be liked by some people and opposed by others. And there are very different communities in Whitstable and you can't please them all.
"But we haven't interfered with Whitstable. It's what we do with Canterbury in many regards - we don't do an awful lot because we don't need to.
"If the private sector don't invest, and individuals don't come down and spend money on housing, then councils can do limited stuff. Our job is to put public money into things which need doing and provide the atmosphere, if you like.
"In other places the locals find their wages being depressed because their local industries are declining. The locals start going out to supermarkets, the local shops suffer and close down and all you get is charity shops.
"Whereas in Whitstable, the people with money have come in, they've done up the housing, they shop locally because that's what they like about Whitstable, and it many ways it’s what has kept the economy going that otherwise wouldn't happen.
"I don't think there's an awful lot councils can do about what I would call ground-based spend. We can't do up houses, we can't make shops stay open."
As for the infrastructure issue - and concern over new housing - he admits there is an issue in some respects but that it is a national problem not one confined to Whitstable.
"Actually, the housing allocation for Whitstable has not been high,” says the local authority chief. “We've concentrated almost entirely on Canterbury and Herne Bay.
"Generally, and every council will say this, we have it back to front in this country. We should be doing infrastructure first and housing second, but that's not the way the funding system works. There's no national funding for doing things like the Thanet Way anymore. The county council probably has enough money to do one village by-pass every couple of years and that's about it.
"It all has to come from developer funding - roads, doctor surgeries, parks, transport, new schools.
"We can't require a developer to put it up front. We have to wait until they have put a significant amount of housing in place then they've earned enough profit to pay.
"So, infrastructure always follows housing and every council will say it's a complete nonsense, but it's what we have to do.
"You could argue the town needs a park and ride. We have a site which is provisionally in the Local Plan, but if you want to make it work the way you make it work in Canterbury, you charge upwards in the town centre car parks in order to persuade people to take the much cheaper park and ride. Again, the idea of raising car park charges in Whitstable goes down incredibly badly so we've never done it.
"Our aim in terms of balance is more to keeping the locals happy. The thing to do is to make the place enough nice for people to live and then people will want to visit.”
As for James Green, of the Whitstable Oyster Company, he is under no illusions.
"My feeling is Whitstable, like it of lump it, is completely dependent on tourism. You wouldn't want to be in the town without it.
"You have to make it as best as possible for those visiting the town.
"Without the tourism where would we be now? We're all reliant on people coming down and spending money. There are some problems with traffic - and I think a park and ride scheme would help with that.
"There's not a lot of people who remember Whitstable previously - but it wasn't a very pleasant place to be as there was no employment and it was depressed. There were no prospects for people getting work or setting up businesses.
"We're not a massive company, but Whitstable is a relatively small town so we're quite prominent. You get companies like ourselves who get successful and ultimately there are a few people who have a bit of animosity towards that. But I maintain that is a minority - albeit a vocal one. The vast majority are advocates of the Oyster Company and what we've done and the prosperity we've brought to the town."