I did the AGI basic course a few years back, it was a pretty good one. The big thing I feel AGI has over the others is their firearm specific dvd's they offer- it's one thing to see how something works or, comes apart in a book, but when you actually see it done, that makes life alot easier. They're on the web, check them out. I can't remember if I was able to use my GI bill towards the course or not, if that matters to you.
Currently "enrolled" in the AGI master gunsmith course. Been going at it for about 2 years now. So far I've only gotten my pistolsmith certification. Not sure if the certification is worth anything, but I've sure learned a hell of a lot. I've got a long way to go before I finish. I've been doing it in my spare time. The video library is amazing. I don't see the master course listed on their website. You may have to call them.