Everything posted by usnavdoc and orbitsurgMD is true, or can be true.
My experience with the Marines seems to have been quite different from usnavdoc's ... for starters, he had a notoriously malignant commanding officer (who was ultimately relieved) whereas I had a fantastic CO who without exception accepted and followed my recommendations regarding treatment, duty status, deployability, etc. I was never placed in a situation where I was running an ER without help or supervision; both of my deployments were to areas that had echelon 2 care colocated with us, and I had easy access to 2nd opinions and help. The sole exception to that was a month I spent on the border of Pakistan/Afghanistan at a SF-funded free clinic that saw local nationals who were sick/injured but denied medevac by higher powers.
Some (most) people are driven to reach their BCP goal with no detours, and I can understand that. I however don't regret or resent the 3 years I spent with the Marines, going places and doing things that I never would have been able to do otherwise. Good COs know to keep their doctors out of harm's way, and there's a lot to be said for the privilege of being THE guy who there to take care of the PFC or LCPL who carries a rifle and kills the insurgents.
The biggest professional disadvantage to a GMO tour is that I've grown dumber in the last 3 years as I've treated mostly sprained ankles and minor sports injuries, URIs, psych problems, common derm issues, etc. I've had a lot of trauma experience, and perhaps a dozen serious medical illnesses (it's not all URIs) ... but there's no way I could step into an ICU as a new medicine PGY2 and not be a danger to somebody. Fortunately (?) military residencies are familiar with the whole GMO thing, and board pass rates are very high, so clearly it's not a crippling setback.