HB is a bit crap compared to Whitstable, though it is MUCH cheaper - it has an older population and also a lot of renters, single people, there is a bit of an antisocial vibe after dark in the town but the outer bits are really nice.
The town centre has lots of small shops, which is great in one way but there's a lot of junk shops and so on. It's quite poor.
Prices however are rising significantly as Whitstable becomes overpriced and people look along the coast. I don't like the vibe in Whitstable any more - it started off arty and interesting and unpretentious, we loved it when we were students...now it's been 'taken over' and got uber trendy and is well up its own arse (sorry!).
I would suggest you visit before you decide - if I could afford Whits I'd still live there as it is slightly safer, and has a more educated population and nicer shops, but HB is very down to earth and most people here are alright. Our street has loads of children, a proper mixture of elderly, retired, young families, our neighbours are headteachers, lawyers, and so on. It's quiet at night and the houses are beautiful and big.
We commute for schools, not far, and there is a huge high school here which no one has mentioned that is far nicer than the one in Whitstable, has a good reputation, great facilities and most kids go there. (we couldn't get a place - vast waiting list).
I have to say HB has a lot going for it... it doesn't have the same highbrow feeling as C'bury but tbh that got on my nerves a lot when we lived there. And the traffic is appalling.
You can actually drive to places here and not be stuck in a queue for an hour. Quite refreshing - same with post offices and so on.