I took one class with John Clements last year, and it opened my eyes to a number of WMA things I never knew. ARMA was one of the first "local" forums I came across, there was a post about him coming out to teach a class near my house. He was a good instructor. At first, I was interested in becoming an ARMA member, but after hearing the part about "and what you learn is not to be taught to anyone else", as essentially a "what happens in ARMA, stays in ARMA" feeling, I realized it's not the place for me.
The best thing about the class is that it brought to my attention there are lots of groups if I learned terms like HEMA, WMA, KDF, etc, that I never knew existed.
I set myself a reminder for the show, and hopefully I can record it and post a digital copy of it for those unable to watch it. My tech is, unfortunately, medieval as well, as I'll need to record it on a VCR (like from the museums) and then convert it to PC format. I'll post up a link if I can get it done and the quality isn't horrendous.