Actual students were considerably more mixed. Obviously individuals vary so if I post how most of his students were totally lost in class, they'll post how one student went on to win a Nobel prize and say gotcha.
Feynman was a world class second type teacher. If you already know how to work with physics equations and solve problems, then Feynman's lectures will improve your understanding considerably. The simplification process he does, gives you a grand understanding of the theory.
Due to this, much of Feynman's pedagogy is not suitable for the first type of teaching. And should not be used as such.
For a first draft, they are incredible.