I don't know much about BTP, but I went through CAP in 2006 and it was one of the best academic investments I have ever made. The training is top notch and people come from all walks of life to study there. It's not competitive in any way so you don't have to worry about impressing anyone or being upstaged. You focus on your own personal growth as an MT performer and over those 6 weeks you will really evolve. I reccommend that you go as a full time student so you'll get the dance training in the mornings. I went in as a science major, who just wanted to see if the theatre was a place I could exist in and my CAP summer really changed my life. I'm now a theatre major at my school and I couldn't see myself doing anything else. If Bill Daugherty is still around there I highly reccomend that you try to get into one of his CAP classes. He is truly inspiring and will help you find things in your voice that you never knew you had. And what better place to study theatre than at a studio that's a train ride away from the theatre district. My vote is for CAP
Going to a musical late in its run is like going to a prostitute late in her shift.