This class was great! Liu is a very young Chinese professor. She has a slight accent, but is not difficult to understand at all. She explains the material very well, and is always available for questions. She provides practice midterms that pretty much show you everything to expect in the real exams. She also does a great job at assigning appropriate homework problems.
Melissa put lots of effort into my class. Even though it was only her first semester teaching, it was easy to learn from her. Her accent is not that hard to understand; however, it is often hard to ask questions becuase she sometimes has a hard time understanding what you are asking. Despite that, she was the most organized teacher I have ever had, and was also the most available for office hours. She cared emensly about the class and went so far as to memorize each of our names, by the first week of class. She returned test's often day of (there were only 14 students in the class). Overall she was a great professor.
Melissa Liu will give you the most straightforward and organized lectures you will see at Columbia. There's no trickery involved in the testing it's just "learn how to do this, this, and this, because these will all be on the exam." She's young and seems to be newer to teaching than most professors, which I guess is actually a good thing. She has an accent but is never difficult to understand. I'm unsure what the curve will be like, but I think the math department is pretty standard with its B/B- at the mean.