I don't like giving bad reviews for professors but... I really wouldn't recommend Ou. It's not even his accent, but mostly his way of teaching that's incomprehensible. He spends all of lecture rambling proofs and was pretty intimidating in my opinion. This was the first calculus class I had ever taken and honestly I learned more from discussion than I ever did in lecture. I believe almost everyone in this class had taken calc in high school, but if you think you have a super good grasp on the subject before you start his class, then you'll be fine. On the bright side, his curves are really great and there's not much homework! I miraculously got a B even though I did terribly on every test.

Ou was kind of hard to understand because of his accent, but he was still an okay professor. His midterms were very similar to the practice midterms.

I have very mixed reviews about this professor. I understand a lot of students' complaints about him, he's not a very good lecturer and he does not even seem to be passionate about teaching. At the same time, he definitely makes an effort to help the class. His practice exams have an identical structure to the actual tests, and I noticed that throughout the quarter he improved in his public speaking and became more thorough with his lectures. Altogether, he's not the best professor at math (you're going to need to already have background knowledge of calculus to be successful ) but don't get too discouraged if you have him.