I have some insight into the BU program. I rotated as a medical student and LOVED IT! The relationships with the attendings are tight and even tighter amoungst the residents. Those were very important to me in applying. I can't tell you enough how important it is that you love the people you work with. The comaraderie is very strong. Residents go out together all the time, play basketball and football together...etc. If you're going to have a good time in any city, it's going to be Boston.
There is also a new academic program, run by the residents and a necessary addition to the program. There are assigned readings in a text book and selected journal articles for a lecture run by a chief resident as well as more formal lectures from attendings. This is in addition to the daily trauma rounds run by Dr. Tornetta.
I would say that trauma is the strength of the BU program as Dr. Tornetta is a fantastic attending. He finds the way that YOU learn best and that's how he teaches you.
Hand is run by Dr. Stein at the main BU campus. He too, is great to work with. Hand call is split between ortho and plastics. You also get plenty of exposure to hand at Lahey Clinic. Rotating as a med student, I found the operative experience to be very strong compared to other places. If you're looking for a small (5 spots) trauma program, BU is awesome.