To be honest, he is not a good lecturer at all. But for graduate class, he do give a lot of flexibility, which is far more than other class. I'm a PhD student and sort of like the way he teach. You have to learn everything on you own, and that's what you should to do in a graduate level course. It would be nice if you can find a good lecturer, but that's not the point of graduate study, especially for phD. What you can have by taking his class is to have a opportunity to spend your time on the project you really want to devote your time. He almost set no restriction on the topic you choose, and this is very amazing. Show you respect to him, and show up in every class. He might not be a good lecturer, but he definitely sharp at your final presentation. He can point out every pitfall you made, give you lot's of critical comment in a viewpoints of senior researcher, which are very valuable. Don't bring your attitude as a undergraduate student to his class, you will be very frustrated. He only guide you, or .... he only offer you an opportunity to explore your interest, and support you.

While you are a RA, you need some time to work on your own research project. Take his class becuz the workload is relatively (very) easy on homework and test, and spend your time on the research part. As a undergraduate, I won't take his class. But as a phD student, I think it fairly okay to take his class. He is quite nice guy. He come UCLA for research but not for teach, and that's the only problem :)

Anyway, if you decide to take 3 or more class in a quarter, his class is definitely a good candidate becuz you can focus your time on other class and get an A easily. Be friendly and generously to him becuz he is more than 70 years old.....