Although I am partial to main campus miami(hopefully they will accept me), I agree with you that Boca has alot of advantages. One thing that is very nice is that the hospital in which you do a lot of your training does not have interns and residents. This means you will have a lot more one on one time with the doctors. The program at Boca seems like a much more personalized experience.
That may mean more interaction with attendings but often you learn the most from working with interns or people who are doing the actual nitty gritty of the work. Also, in a major teaching hospital you see a large breadth of cases you don't see in a less academic established teaching hospital.
On a side note, I was looking at FIU's website and it seems its going to get affiliations with Mt. Sinai Medical Center in Miami as well as the Jackson Health System (don't know if that means Jackson Memorial-Umiami's teaching hospital), and Miami Children's hospital. I found that interesting. miami children's hospital is one of the few children's hospitals in Fl. that is highly ranked as a pediatric hospital in USNews and someone else can correct me but I believe it along with Mt. Sinai Medical Center also have affiliations with Miami's med school. But someone who knows more would have to confirm so don't take my word for that.