Truly horrendous experience. He is not interested at all in teaching. He copies his own notes on the board quickly, mostly in theorem-proof-theorem-proof-theorem-proof mode (obscurely, and he often screws up on the board too), and then gives you quizzes and exams that have nothing to do with what he talked about, or even with the contents of the textbook!!!. He marks no transitions, and he makes no emphasis on important points or essential contents. And he doesn't allow formula sheets on exams either.
As a result, the grading of homework, quizzes and exams is absolutely unfair, so not only will you learn nothing from his class, but your GPA will suffer unduly.
Any resemblance between teaching (even bad teaching) and what he does in a classroom is entirely coincidental. I am truly amazed that he is allowed to teach independently at Columbia.
The worst is I actually was very interested and excited to learn linear algebra. I guess I'll have to buy the Schaum's Outline...