I was in one for two years...............
It didn't work out well for me, as i begged to be moved to public school after my sophomore year.... (Yes, i wanted to be around girls, what can i say...i wasn't suffering all that badly from SA at the time)...also the religion which was involved in it was a problem since i've always been a closet atheist. (Still haven't mentioned that little ditty to my parents, even though i'm 27)
The school itself wasn't terrible. I did make friends there, who i never really spoke to after i left. I guess it can vary a LOT from school to school depending on living situations, meals, the goal of the school, whether it's coed, etc. (I had a few "bunkmates" which were absolutely HORRIBLE people) The main thing.........expect to have VERY little privacy.