We've lived in Wells for over 20 years. We really like it.
Both our children were born here and so we've been through the local school system. There are basically two primary schools (one at either end of town) and where you live pretty much decides which one your children go to. There is also a Catholic primary if that is a consideration for you. The two main primary schools are pretty similar as far as I can tell. There is one state senior school and one fee paying one. Both my children went/go to the state senior school. They have both been fine there. The oldest has just gone to university and the youngest is in year 12.
Wells itself is a lovely little town (although it is a city, it's tiny). Everywhere is walkable, whichever end you live. There are a few chain shops (New Look, Factory Store, WHSmith, M and Co) lots and lots of coffee shops, some nice independent stores and four supermarkets (Tesco, Morrisons, Lidl and Waitrose).
There are very few properties to rent in Wells and they go very quickly. The range for a 2-3 bedroom is about £550-£700pcm. There aren't any bad areas to live, but the further up the Bath Road you go, the further it is into town. If you drive, the surrounding villages are nice (Dinder, Croscombe, Coxley, The Horringtons) but if you can't drive, be aware public transport is fairly dire and expensive.
It's an incredibly safe place to live (and I've lived in a lot of places). There isn't a lot for older children to do, but there seems to be plenty for younger ones and there's supposed to be a new soft play opening soon.
As I said, I love Wells and it's been a great place to bring up children. I would imagine they will move on to find a bit more excitement when they've finished university but I think most people who leave end up coming back when they have their own family. If there's anything else you want to know, just shout.