I live in London and went to art school here so maybe I can help:
The big 3 art schools in London are Goldsmiths, RCA, Slade –
Goldsmiths: The MFA programme is interdisciplinary (does not distinguish between painting, sculpture, etc.) the group critiques and individual tutorials are probably the most theoretical of the 3 schools. Also Goldsmiths (to disagree with 'newamsterdam') actually has an excellent academic reputation in the humanities and social sciences (its visual cultures, anthropology, and psychology departments are amongst the best in the country) and you will be able to 'audit' classes in other departments relatively easily - however you should be aware that most of the departments (outside of the art department) have a particularly radical left-wing political position/agenda.
RCA: The MA is split into completely separate programmes for Sculpture, Painting, Photography, etc. and there is relatively little crossover (although this is changing). Personally I also see it as the most conservative of the 3 - it produces very commercially acceptable artists (read: "unchallenging"). This is defiantly the most trendy art school in London at the moment, as the increase in university tuition fees means that art students want a more direct route into commercial gallery success. However I should mention that Ute Meta Bauer, the new head of Fine Art at RCA is really tiring to make the school more interdisciplinary and experimental etc.
Slade: The Slade is split into MA and MFA these programmes are essentially interchangeable except that on the MA you do a longer dissertation and take additional art history classes. The Slade is somewhere between Goldsmiths and the RCA and generally produces an interesting mix of more commercial and more transgressed works at the degree show. You will also have access to UCL and its excellent academic departments.
P.S. Obviously this is an oversimplification of the 3 schools so plase message me if you have more questions
