I haven't taken the BSAC course, but have taken a PADI equipment specialty. My PADI course was conducted by someone who has done repairs for over 40 years and services for the busiest dive shop in the state as well as for quite a few other dive shops. With that disclaimer, my class was incredible. He focused mostly on field repair concepts since that's what most divers are going to use. I am certified to teach the course and from the outline, there is a decent amount of flexibility allowed to PADI instructors, so I'd personally recommend finding someone with a lot of experience. While I'm certified to teach it, I happily send my students to the guy I took mine from because I know he can answer ANY question thrown his way.
