There is WAY too much negativity on Lei He here and I won't stand for it. He is a great professor. Prof He was always willing to take the time to answer questions and provide additional explanations, and they provided a variety of resources and learning opportunities to help us succeed. They were also very fair and consistent with their grading.
I highly recommend taking a class with Prof He. While it may be intimidating at first to have a professor with a bad reputation, I can assure you that Prof He is actually an amazing instructor who cares about their students and is dedicated to helping them succeed.

Not good at teaching the material. Luckily, during my quarter, we had good TAs. Make sure to go the discussion sections because they really helped. Fair grader and tests aren't too difficult. Got an A- in the class, but it was because I read the textbook and went to discussion sections.

He really doesn't know the material, very unorganized, lecture is only confusing. Just read the book. He is a fair grader but you will have to rely completely on the TA. Worst teacher I've ever had.