I don't know much about CA except for a book that I have, I'm not sure of the name right off the top of my head but it has pretty much every one of his exercises with tons of pictures and information, but from that book I've gained a dislike of him.
It seems like a lot of his methods depend on turning the horse into something that won't do anything without human intervention. Like his exercise where the horse is supposed to go in a straight line at whatever gait you tell them until you tell them to stop. I personally want my horse to think for herself. I want her to be able to choose where she think the safest place is to walk on the trail instead of relying on me to tell her.
He does have a few great exercises, I really like how he explains flexion and disengagement of the various body parts in his book.
I'm sure it works great for some people and I'm happy for those people but Lacey and I will never be one pairs that has success with that sort of thing.
I'm with Spastic Dove, if I had to choose a trainer to apprentice with it'd be Monty Roberts.