When I sent my son to a small Catholic school, what I liked were the small classes, and the involvement of fellow parents. But most of all, the enforcement of behavior standards toward classmates and the variety of group activities available were exemplary. There was no abuse allowed, and that was important for my learning disabled child. This particular school did not have teaching nuns, so I can't speak to that. Also, although we are not Catholic, the religious training was not unreasonable.