I purchased the MGE study course for the April 2010 Power exam. I found a couple of the sections helpful, but overall, I didn't think it was worth it. The explanatory material is very shallow and it had not been revised for the 2010 exam. Fortunately, my employer reimbursed me.
I did use the Irvine Institute class and found it more useful. The online course was one of the few that followed the NCEES outline. The Kaplan sample exam was okay. The NCEES sample test is the best resource. I like that the Irvine Institute group went through every one of the NCEES current sample exam questions and gave more detailed explanations of the solutions.
I don't know if I passed, but I was able to finish the morning and afternoon exams each with an hour or so to spare.