Horowitz is an awesome dude. Gives very reasonable homework and exams, and while he simply lectures from the book a lot of the time, it was still very clear and helpful. He is always willing to answer questions.

Professor Horowitz is a leader in his field of GR and String Theory so it is an honor to be in a class with him and obviously he is knowledgable. I felt he was a bit robotic teaching, not much flow or emotion. Nonetheless he gets the points across. Class is pretty easy considering it is upper division. HW is short and tests are not too bad.