Hey, I've been at Sidney for two years now and know quite a bit about it because I help with all the access stuff, was on the JCR etc. My wonderful next-door neighbour Priya has done a very good job of giving you the details. If you have any specific questions PM one of us (Priya's exams are over but mine aren't over until Monday).
I've got quite a few friends outside of college, and from what I can tell we are comparatively bad for food and accommodation. We are very good for welfare provision. The medics work very hard, but I can't think of anything in particular which would make their experience at Sidney much different from the medic experience at any other college. A girl from my school is coming up to read Medicine in October so if you want up to date admissions information (what to expect, etc) then I can ask her to tell me a bit more. Otherwise there's the Oxbridge admissions site which has profiles about people's applications, including their interviews, and which is pretty good in terms of giving you an idea of what to expect.