I have not, but I read his writings regularly and have watched some of his videos. He's presenting information that's hard to come by otherwise. I have every reason to expect his classes would be good.
I attended his 'Arc Flash Study Workshop' recently in Denver.
It was excellent. He is a knowlegeable and articulate speaker. His material is comprehensive. There was absolutely no wasted time or effort during the two-day event. I would highly recommend his classes to anyone.
I took his Power Systems Engineering Class last year in FL. It was a very informative class with great examples. If you haven't done much or any design I would recommend it. He shows you how to do a calculation by hand and then will have you do one. There were no complex design or coordination studies done as time would not allow and some people in the class probably do not have the math or other background for it. It is a great introduction or refresher to lots of material. If you would like any more information feel free to PM me.