Greene is a nice man, very friendly. His way of teaching is intuitive: present the problem, present the solution, ask "Why?" very loudly, and then explain it.

This is a very difficult class, and can be hard to follow. Additionally, Greene's handwriting is absolutely terrible. The material is also nonstandard in the sense that Greene provides his own proofs for many things that are not found in other textbooks. You should read many textbooks for this, but try to follow Greene's notes, however difficult that is.

The one thing I appreciated about this class was that the problems were challenging enough that you couldn't find answers to them online, which means you really needed to think and challenge yourself to solve them, which was rewarding. However, it was a lot of work, and was really difficult if you didn't follow lecture. Would recommend doing HW in a group.