I just finished the Basic Sciences at SGU, and will be starting in NYC for clinicals this Fall.
Grenada is pretty nice. The campus is gorgeous. I didn't live in the dorms, but the new ones are pretty small for two people. It worked out better for me to live off campus for the entire 4 terms there; if you really dislike your living situation, there should be no problems finding a place off campus (you CAN live off campus first term, despite what the school tells you).
I've found that the campus is generally kept up pretty well, although students tend to start abusing the facilities (especially restrooms for some reason) once the term starts going.
I think the school tends to sugar-coat things--especially how nice the people are. Don't get me wrong, I really had no problems with anyone. One thing you learn while being down there is that being patient and pleasant goes a long way! I guess many of the Grenadians get annoyed with students, especially the immature ones who complain at length about being there. It is a third world country, after all!
The academics are pretty rigorous (as with any medical school), but definitely doable. I heard a lot of horror stories about medical school and how you'll never sleep--total B.S. If you keep up with your work, there's no reason why you can't get a good amount of sleep. It takes a little while to develop your own study style, but once you find what works for you, you should be ok.
I'm getting ready to take the USMLE in July, and so far I feel that I am well prepared. SGU has an excellent reputation for first time pass rates on Step 1 (the most recent class had a pass rate of 92%), as well as for its educational program overall. I don't regret going there.
Feel free to PM me if you have any other questions--I know what it's like to start your journey down there, and it can be frightening. But you can do it (esecially if I did)! And yes, I've met students from all over (India, Kenya, Bahamas, U.K., Czech republic, Egypt, USA, Canada, Caribbean...)
Good Luck!