When it comes to grading, there is too much variance, and it's really a roll of the dice as to how the professor you end up enrolling under grades. A lot of them are too strict despite being literally grad students and it being the first time they're teaching. If you can find an established professor who's taught the course before at least a few times and has a history of giving out As, then only can you be confident in their section being a good one. This will require you to do some (or a lot of) research using BerkeleyTime's grade distributions feature, but it's worth it imo.

As far as workload is concerned, usually R5's are said to have the lowest workload, relatively.