Hey,
I'm not pre-med and I don't study at Imperial but I live with a bunch of Imperial students. We all stay with pure student livingthat's based in Hammersmith. And personally I can say there is a hospital near by, because I always see the emergency cars drive past. Honestly it's not as central as it could be but I really like it. It's a nice change from living on campus, you get a lot more independence. I moved after my first year of uni and am really enjoying it. A lot of the other students are second and third years too.
Sorry to hijack your med thread, I just wanted to throw in my 2 cents.