Some topics are more difficult than others, overall, the class isn't insanely hard, but it depends on how well you grasp the material and who teaches it. In my class, our only grades were quizzes and exams, but the optional homework is useful for studying.

Zhong is a nice person but not the best teacher, she has gotten better as the semester progresses and I've heard she's good at teaching one on one during office hours, but her lectures tend to be somewhat fast-paced and sometimes she forgets to explain things.

Actually study for the first exam, most people didn't and their grades tanked.