I've been to Stone Tech, This Old Grout, Stone Pro, helped Cameron grind down his Dad's showroom one weekend (which I considered a class because I learned so much), a local stone restorer guy here in town that put on a 2 day class at Pro Line and Easy Stone Care for classes. They were good classes and I learned a lot, I don't have any negative things to say about any of them. The Easy Stone Care class was the best for me, I already knew quite a bit about soft stones at the time, but I learned a lot about granite, which the other classes either didn't go over granite or only showed how to seal granite.