The generally perpetuated (although I don't really think it matters, so take it with a grain of salt) rank order of the Caribbean schools is:
1) SGU
2) Ross
3) AUC
4) the rest
Personally, I hated Dominica. I thought it was a miserable place to be. While there were some fun times scattered about here and there, I don't miss it and have no plans on going back. However, that experience and the school thus far has done an excellent job of getting me where I am right now. I did not apply to SGU or AUC, for a variety of reasons, and knew as much as I could about what I was getting into when I went to Ross. So, I was prepared as much as I could be before leaving.
More students transfer from AUC to Ross than vice-versa. I think this will begin to change as AUC continues to get more clinical sites in the U.S. This is key - do your clinicals in the U.S.
Right now, I'm in the U.S. doing clerkships with U.S. students from both M.D. and D.O. programs, as well as other Caribbean and European (e.g., Hope in Poland, etc.) programs. The point is this: do whatever you can to make sure that you get to the U.S. to do your clinicals. It's not really going to matter, in the grand scheme of things, where you went to do your pre-clinicals. There may be some perceived difference in particular students from different schools, but remember you are an individual and you will be judged as an individual when you are on the wards. No one will look at you as a representation of your school, unless they've had a consistently bad experience with EVERYONE from that particular school - and then, once you prove yourself after a week or two that won't matter any more anyway either.
Good luck whatever path you choose. Do your homework. And, remember, no matter what anyone else's opinion is, it's mostly up to you how far you want to go and what you want to do with your education.
-Skip
MSIII RUSM