I'll bite:
I took a Kaplan course. By chance, I had a great teacher and it really helped me review my material. However, Kaplan was an effective learning tool for me because it forced me to study before every class. I certainly wouldn't have done as well without that constant pushing. If you feel like you can study efficiently and for extended periods without a "class" forcing you to, by all means skip the class. The material isn't overly difficult, theres just a lot of it, so you really have to jump in and commit.