If you want juet pure derivation of formulas take him. He doesn't do any problems in class and he expects you to know them on the test. His first midterm is easy, and his second midterm and final are the hardest exam ever. His TA's are lazy and do not know how to help you. I think he is the worst professor for physics, because he doesn't teach you anything, he basically wrties whatever is in the book on the board. He does alot of demos in class which is intersting, but it doesn't help you in the problems. I think you are basically on you own, and you should rely on the book for understandin of the material. He is nice , but what does niceness do for you?