Just so you know, you don't get guaranteed university accommodation since Bristol is your insurance choice. You do get to apply for it later than the students who have it as their first choice but I'm not entirely sure when that date it. Bear in mind, you may not get a chance to apply for the halls others recommend to you.
I would say that you should stay away from Stoke Bishop residences if you care more about being close to uni than being in a more social area. It's a 15 minute bus but a 40+ minute walk. But if you go outside of Stoke Bishop, it'll be self catered unless you go to Clifton Hill House which is really lovely on the inside but is on a steep hill. Additionally, there are only three residences that offer both en-suites whilst being catered: Churchill, Badock and Wills. Wills is meant to look lovely but is very expensive. Badock has a lot of parties but I wouldn't say it's got a good interior, I personally find it very depressing. I've only been inside the eating area in Churchill but it seems nice, probably the better place to go if you want both catered and an ensuite. Also bear in mind that if you stay in catered you don't have a cooker, oven or freezer. All of your hot food will either be from the cafeteria or cooked in a microwave. You will also be sharing a pantry between a floor of people and they do have a tendency to take food, my friends in catered (Badock and Clifton Hill House) have both had to keep food in their rooms because people have raided their stuff.
I unfortunately can only give other people's experiences since I stay in self catered. I'm sorry if I give a bad impression of catered accommodation, it's just what other people have said it's like.