Hey I broke in a wild stallion this year, & I mean straight from runing on the ranges wild, he's a total darling www.wildhorseproject.blogspot.com
he will probably one day be used for lesson also. You just teach stallion the rules and then they are generally quieter than any mare or geldings.
If they are used in lesson I would say go for it no one will be using crazy studs for public lesson, I bet these stallions will be just as good as any mare or gelding, totally agree with everyone elses comments on the subject
Stallions definitely intimidate a lot of people there are some very bad stereo types out there for them