While I don't know that many of the details about military grants for med school, I do know about military life from my own experiences.
I would think hard before accepting this type of aid. Not because the military is bad or anything, its just not for everyone. I would only consider it if you already inclined toward the military. I saw so many people (from peons to physicians) who were constantly complaining about being in the military. Those most unhappy were those who used the military for education (college or med school).
My point is just this, the military is a different lifestyle. I don't know for how many years, but you will be stuck in it regardless of what you think about it (assuming you take the grants).
I have also heard about people having problems getting residencies they want, but don't know much about that.
