Another vote for DO > IMG. A couple things that I'm noticing:
1) US schools are increasing in size and number (both MD and DO schools). This leads to more American grads competing for the same number or slightly more residency slots (PGY training slots are not increasing at the same rate as schools enrollments).
2) I'm thinking in 5 years or so from now as these increased class sizes start graduating and seeking PG training, it will become nearly impossible for a DO or IMG to match into a competitive specialty ACGME slot.
3) When ACGME residencies in competitive specialties start filling completely with US MD grads, the DO students at least have the AOA residencies to go into. For instance, it is incredibly difficult for a DO or IMG to land an ACGME orthopedics spot; however as a DO for an AOA spot, it is very doable. So if you're set on a super competitive specialty, that can become a reality.
4) It seems in general, the clinical training sites for DOs are better than carribean grads. At least here in NY, we train at good hospitals many times alongside students from NYU or Einstein, places like NSUH, whereas the carribean students seem to be jammed into small, poor community hospitals with poor education value by comparison. When I've rotated at those programs, the education was not as great.
5) Out there on the interview trail for Gen Surg, I do run into IMGs, but many times they are interviewing for pre-lim spots, while all the DOs I know are interviewing for categorical positions.
BTW, nothing against carribean IMGs, I've rotated with a bunch of them, and many know their stuff and work hard. I just feel bad for them. If I had a nickle for every time I've heard, "I wish I would have went to a DO school if I knew what I know now..."