I missed it a bit when I first moved away, but not anymore, and I wouldn't move back. Brighton thinks it's so cool and cosmopolitan, but it's not really, it's just a few ageing hippies, gays and some art. And a load of chavs. Same as most other cities really. It's much dirtier than most other cities though.
Brighton's a far superior place to those Northern hell hole towns like Burnley and Bradford etc, but I don't think it's much better or worse than any other reasonable cities in the UK. And for a city, it is very small, you get bored going to the same places all the time very quickly. It's helped as a city because it is in Sussex, which is a great county, probably 5th or 6th nicest in the country.
Art? The art scene in Brighton is utter pants. For a city so allegedly steeped in culture there is not even one decent art gallery.