Coming from London arent you going to find any move quite a change?
Bristol will make up for alot of things you may miss, but unless youre living in it, with young DCs and without driving I dont expect you'll get there too often. The train station isnt in central Bristol.
As this isnt RL I wont beat about the bush . . .WSM town centre is a dump and I wouldnt go there day or night. There are always some drunks or druggy types hanging around the high street, sitting in the parks. WSM has cheap housing for a reason, its not remotely desirable.
You mention Margate, I think its comparable - lovely beach, lovely period properties, but no shops, no life and the sort of social and economic deprevation that makes me feel very uncomfortable and depressed.
I think without driving it will be difficult around here, unless you are happy with suburbia, you'd need to be central to a larger town. Id look at what areas you could afford in Bristol, if not Wells is lovely, Taunton or at a push Bridgewater.