1) know each schools usmle pass rate
2) know how many MAKE it to the boards with their class (is a poss rate of 90% means nothing if only hafl of the entering class make it with their class
3)can you get licensure in all 50 states (or the ones youre likely to practice in?
4)can you get the residency you want from that school (they aren't all equal)
5)are all rotations acgme approved? If not you can run into trouble 10s of thousands of dollars and several years later.
6)cost, lifestyle for the two years etc.
Its not a simple question you ask with a simple answer. An aspiring FP doc who wants to practice in nyc may have different options to an aspiring Er doc who wants to go to california.