My work used to bring in the Decker folks for trainings onsite. We stopped a few years ago before I could get in (my manager said I had decent skills already and there were others in more critical need of the trainings). I've hear nothing but positive experiences. It was a small group training where you give multiple on the spot presentations and the pros helpfully critique and provide help. You learn stage presence and how to not fill silence with filler words and such.