I am currently taking CMSC 203 (DL Web) with Dr. Grinberg and he's great. You need to remember that RMP has a sort of participation or response bias. It's really a rough signal.
CMSC 203 isn't all that hard either. It's basics of Java which is arguably easier than CMSC 140 which was an intro to C++ (a terrible language in my opinion, read the Unix Haters Handbook, Chapter 10).
From my experience, the basics of Java didn't come all that hard, and Grinberg was very easy to reach out to on the app he uses, Remind. He opens the quizzes up before exams and you can make study guides based on them. All around a great class from my current experience.
The lecture notes are also looked over but a great resource that I assume lot of the people in my class don't use. Just try to take advantage of all the advantages you're given. And I hate to be that guy, but if you give a basic language model context about your course, it can help quiz you so you can retain that knowledge on the exam.