Because Ross has/had more students, more people will have heard of it. That doesn't mean the quality of the instruction or the grads it turns out is better or the same as these other schools. SABA is newer and so likely fewer people have heard of it. I don't know about the quality of the education there, but the fact that not many people fail out and that they have a high board pass rate suggests that they are doing something right. I think it would be worth extra money to have a higher chance of passing the boards, if I were in your shoes, but I can see your point about not wanting to pay for St. George U. I still think if you look at the big picture you would be better off at a DO school and it doesn't seem that you're that far away from being competitive. People have these prejudiced against DO schools but the reality of the situation is that they have a much, much lower attrition rate, and fewer students, than these Caribbean schools. Furthermore, they have their own residency programs as well as allowing their students to match out into US MD programs. Also, the students from those schools that I have worked with have been just fine.
I think that premeds have a lot of unrealistic ideas about what med school and practicing as a physician are going to be like. How could they know what is ahead of them? I can tell you that the quality of instruction in med school is important, and it's not all your "motivation" or you "buckling down". Those things might allow you to pass and even pass the USMLE, but the one on one and small group teaching in med school is super important, and I'm just skeptical about the ability of these med schools that have hundreds and hundreds of students to provide that. Also, their ability to control quality of instruction during 3rd and 4th years, where students are spread out at all these different hospitals, has got to be questioned. I worked with a student from Ross recently, a 4th year, and he was very smart, but I and others who worked with him are still worried that he won't get a good residency. He also basically said that setting up his 4th year clinical rotations was basically all up to him - trust me, that's not another thing you want to add to the stresses and other responsibilities of med school.
There are just a lot of qualified people fighting for these US residency spots and you need to look at the big picture. If you are willing to limit yourself to psychiatry, family practice, general internal med or physical medicine/rehab then you may do O.K. I still think that US schools, and perhaps other alternatives such as optometry or PA school, need to be looked at very hard by people considering these Caribbean schools. That or spend another year or two improving your application. I doubt that you or most of the other folks on here will listen to me, but I know what I'm talking about in terms of where these Carib grads end up. I wish nothing but success for anyone who has the grit to get through those schools, but it's not just a matter of going down there and graduating, even if you are able to do that. There's a lot of crap involved in getting a decent residency and getting a license.