Have a child soon to be in a similar situation, so any thoughts helpful.
For going from highschool to college there is almost zero negative, since it's the nth time you've moved and had to rebuild a social structure.
Consider the number of total school changes for an average domestic student is 3. K-5, 6-8, 9-12, and in those cases they keep their friend groups.
Another upside, in retrospect: you end up getting to see, up-close, a huge range of the social/cultural/political landscape.
It's hard to demonize an outgroup much when you at times were that outgroup -- or were at least, in the abstract, some outgroup. You end up forced to confront (deep-down, maybe mostly unconsciously) the arbitrariness and...malleability of a lot of things. You end up with a lot of tolerance. I'm thankful I had that experience, even if it was at times not particularly fun.
I think it's fundamentally about increased tolerance to uncomfortable/novel situations.
Which suck. But apparently it is a learned skill! Or at least coping strategies are.
I'd be fascinated to see a study on adolescent coping strategies in non-military vs military child populations.
I went to several DoD and civilian schools, NC (dod), NJ (civ), Erie PA (civ), Okinawa (dod), NJ (civ). I would say the standards are higher in DoD, mostly because of standardized curriculum. In civilian world, the variance is very high. In South NJ things were more rigid, in Erie more lax.
As for "not having social groups" this can be a plus, looking at my civilian counterparts in high school. It has pluses and minuses, but being an outgroup in high school let me leave that stuff behind much easier on my way to college. It makes me an alien to most of civilian world, but many benefits.
Housing is provided in the military.
AMA. I am anecdotal, but I have seen both sides at all three levels split down the middle.