I am a first year student at Warwick studying History, I currently live in Sherbourne. I really love it here. Accommodation is very nice indeed, on-suite, big kitchen etc. Whole place is quite modern compared to other halls on campus. Sherbourne is right near the Business School in terms of location. It is situated alongside Lakeside and Heronbank.
Do not worry about the distance to central campus, people who have not stayed / or been to Sherbourne over exaggerate the distance. It is no where near as far from central campus as Westwood is. Takes me 10 minutes to walk to all my classes and seminars.
In terms of Sherbourne being quiet, don't believe that either. At the end of the day though, it is pot luck who you are with in regards to flat mates. I have been really lucky, met some great people. We are even living together next year in Leamington Spa also. Flat is quite international but we all mix really well. Out of 12 people, only 2 keep themselves to themselves, that is because they have a lot of friends from back home they go out with. My flat usually go out to clubs or for a drink a few times a week. There are often flat parties also, we have become quite good friends with some of the other flats in our building.
If you have any more questions, please feel free to ask. Sherbourne has been great to me.