The guy is really smart and really cool/down to earth. He told us he made a mistake in letting one question get the best of him, taking way too much time on it and then not being able to finish a section, or not able to finish it well (I can't remember exactly), which I guess accounted for the few point drop. Take that info for what it's worth, but the guy is definitely knowledgeable. I don't know how the others did in my class, but I had an 11 point jump from my first diag to the real test, so I found the course in general to be helpful. I was usually burned out after the 4 hour classes, but he would go out for drinks with some of the other people in the class after it was done sometimes. Chill guy. Take him if you can.