St. Georges has been around for a long time, and they have highly esteemed faculty from top-rated US med schools to lecture. The school entices faculty from the top schools with vacation packages and competitive pay in paradise. So they attract plenty of good people. The medical education part isn't a problem as long as you can keep up. They also have clinical rotation sites in the US where you can network. So if you can pass the boards and graduate, then you're probably going to be okay even with the residency crunch, as long as you want to do a fairly non-competitive residency like IM/FM, peds, or OB/GYN.
But putting all that aside, I personally don't think the Caribbean would be ideal for me. I like my Diet Coke, Target, and other modern conveniences too much. I really don't think I would enjoy studying medicine in a foreign land where many of the comforts of home are nonexistent.