Boys' gymnastics is also way smaller. There is no XCel to serve boys who want to compete in gymnastics but don't want to be really strong optionals, so boys' JO teams (the sensible ones) deal with, retain, and compete those guys as well. The top boys' programs do have boys doing crazy hours and homeschooling, but there just aren't as many of them around. If you want to see the crazy, look at Future Stars -- not the gyms that have a program where some guys learn some skills, but the gyms that are sending teams to regionals and nationals. Those guys are breathtakingly good, and laid back isn't an adjective that would get within 40 feet of them, I'd guess. Because of the way the age thing works for boys, my beloved child, who is taking a more leisurely tour of the levels, will likely run into them for the first time in his meets next year, but they can't zoom away from him into L10.
It's interesting to me how the rules are different -- the "stretch" on the girls' side is the low age limits for moving up the levels, so they can zip up to L10 if they are developing skills ahead of the curve. The "stretch" for the boys is in the lack of limit on difficulty for most skills in their optional routines. If an 11 year old L8 can do C and D skills, he can compete them.
The crazy (for good and ill) is there, but it is surrounded by a lot more laid back stuff IMHO. And as Skschlag notes, no matter how fast your crazy train goes, with a boy the station really can't be reached until after puberty.