I would go for CHH again myself, but it depends what you're looking for. CHH is closer to uni which is a real plus, it's not just about the walk, it's about being able to go back and forth between lectures even if they are quite close together and also being so close to the library that if you are having an essay cris you can pop over for some books, or even just work there if you find your room too distracting. Also, being close to the union means you can join more societies and take more classes and things, because it is literally 5 mins away.
Oh, and don't presume that as an English student you won't have any 9 am classes. I have had a 9am on Thursdays all year now, despite the timetable changing in the middle of the year. And I am not a special case. So if this
happens to you, you will thank God that you can get up at 7:45 rather than half an hour earlier or more. Especially if you've been out the night before...
Rooms are supposed to be smaller in CHH but to be honest I think they are a decent size. If you want to avoid South Wing with the narrow rooms, then ask for a mixed corridor, there is only one there, whereas Fry Wing is all mixed and there is space for a keyboard.
The formals aren't that often but to be honest I don't mind, I think you get bored of them pretty fast anyway.
You'll have a bigger chance of getting into CHH if you are very arty, dramatic or musically orientated (since you want tot bring a keyboard I presume you are and you'll want to make that an important part of your personal statement), doing English (there are a lot iof English students in hall this year and I think this is because the warden studied it herself) or are French or have a link to France (the warden is Frenh herself so there are quite a few).
Another thing, I thought Wills was now more expensive than CHH because they have renovated.
Being close to the clubs, pubs and bars (walking distance for all, not the case for SB people who usually take cabs which gets expensive) is great too. It made me go out more than if I were in SB, I'd get too lazy to be honest.
The only advantage to Wills in my opinion is having that sense of community in Stoke Bishop. People often go to other halls' bars and get to know people from other halls by walking home with them after lectures. In Clifton, we don't mix as much with the other local halls and hardly ever go to SB (I've never been myself). So you'll make most of your friends in hall. This will not be as much the case if you are in SB possibly (though not for sure).