We used Learning Tree, and I found it to be a good review of everything you need to know for the test. The instructor is critical to a good class. If he keeps you engaged you will learn and remember things.
But, I would not recommend that a boot camp is not the only thing someone does to prepare for the test. You should already have a good understanding of project management, and you should be prepared to do additional review and practice tests before taking the exam.
One key thing is to schedule your exam within a month of the boot camp, otherwise you’ll forget a lot. I did my boot camp in the beginning of December, and there was no way I was going to get to the exam within a month. Then other things came up, and I finally took it at the end of June. I could have eliminated a lot of extra studying if I took it within that month window.