I took the Kaplan course and I was pretty happy with it. I signed up for the class that teaches for the December exam, but I was able to stay on board for free until the February exam. I am awaiting my score so I can't provide quantifiable results, but I appreciated that they not only helped you prepare for the test; they helped prepare you for the test day itself. In that sense, I think Kaplan or something similar can help you learn how to calm your nerves by testing you in a real test-like setting. It seems that a lot of people who study alone do very well when they practice succumb to nerves when they take the real test. When you take a class you get the experience of going in and taking a proctored exam with other people. A bonus is if you decide to go in really early to practice waking up early and taking a test
That said, I think whatever course of study you choose depends on what you're willing to put into it. I put a lot of time and effort into the class but many people don't (even though these courses are very expensive and your future as a law student depends on your success). I work a lot better with structure and someone checking up on me to see how I'm doing, but that's not the case for everyone. There's no blanket answer to what's going to help you perform the best, but I just wanted to provide my experience. Good luck!