Don't get me wrong; as I mentioned above I've found his lectures on both introductory physics and gravitation to be extremely enlightening, as did many of the Caltech students he taught (who were, by the way, just normal intro physics students, albeit at a selective university). His teaching can be highly effective when matched to the proper audience.

But that's just my point: there is no 0 to 100 scale of 'goodness' in teaching. And Feyman, regardless of his brilliance, doesn't sit at the top of hierarchy of teaching excellence. It's about fit between the student and the delivery the instructor. The Feynman lectures in video form can not be the pinnacle of physics instruction because they're fixed, not adaptable to the needs of different learners.