I took this class during the summer because I've heard horror stories about Econometrics, but it turned out to be a great class and I'm definitely considering taking Advanced Econometrics.
David Munroe is amazing. I cannot emphasize how great this guy is. He explains things in a straightforward way and his lectures are concise (rendering the textbook useless-- don't buy it). David is also incredibly approachable and patient. He answers all questions asked in and after class, and will respond promptly to e-mails. The material in class can be dry sometimes, but David seems to realize this and usually makes a joke or two to lighten up the mood. He also prefers economic intuition to tedious mathematical proofs, which is perfect if you're not so crazy about the math side of economics.
The TA, Jessica Tressou, was also great. She uploaded comprehensive notes that served as good review material for the midterm and the final and held weekly review sessions. Like David, she was also very approachable.
I'm not sure if this was because the class was taught in the summer, but the atmosphere of the class was very relaxed, friendly, and not intimidating as all as I thought Econometrics would be. Definitely take a class with David Munroe if he teaches it again-- he is by far better than any math/stats professor I've taken at Columbia.