I really enjoyed Doug's half of the course- a LOT more than Ali's. Doug is very engaging, helpful, and his tests are straightforward. He's a super cool guy and wants all of his students to do well. The class average before he started his half of the course was low, and he reassured us that he would help us out. Just make sure to study enough for the test. Only 4 exams, each 25% of your grade. Go to OH if a topic in lecture doesn't make sense. I recommend reading the textbook to make sure you understand the concepts.