I can't resist joining in even though it's a zombie thread!
There are things I like and dislike about it.
I do like the pebble beaches but I prefer them outside the city centre - if you go a little way in either direction it's alot quieter and without the litter.
I really like it when it is wild and windy by the sea. It is also nice that it is a sea-side town that doesn't entirely shut down in winter, and has shops, bars, restaurants etc that continue to be fun and busy all year round.
I find the "quirky-ness" and somewhat-forced artiness a bit annoying. It's all a bit too self-conscious to feel "real" to me, and as a result doesn't actually feel very laid back. A bit like competitive
People refer to it as London by the sea. It isn't really as it's very monocultural and the vast, vast majority of people are white. This can feel a bit lacking, for want of a better word, if you come from London.