I would not recommend taking an R1A-R1B course if you don't have to. The workload varies, but the content tends to be bland. (After all, the focus is on writing skills, not subject matter.)
An exception to this is L&S R44, a 5-unit course offered every fall. It's pretty intense (I'm currently finishing a late essay, the third paper this year) but I enjoy it a lot. It's one of those courses that only great universities can teach well.