Professor Ly is a good professor. She always makes herself available during her OH, is willing to take the time and discuss confusing subject matter, and is an overall amicable person. While it's true that many of the lectures repeat exactly what's in the book, it is by no means dull because in class you can further discuss questionable/interesting subject matter. Also, it's not all that difficult, if you take the time to keep abreast of the readings. If you don't, then that's on you and your grade.