I used it and managed to pass 1st time. I really paniced when I was doing airlaw, but after passing the exam I did not think it was that bad. I found Met the hardest, strangely enough I got 96% for it. I thought human factors was a walk in the park and Nav the most interesting. I prefer mathematical things.
I had a tutor to go through everything with me. He spent about 4 hours per subject, then I did a mock exam, we then worked on my weak points. Then I got to do the real exam. I did the whole lot in about 5 days, but admit I did go through the next days syllabus the night before. just to get a little prepared.
I was tempted to get the confuser, but thought it was sort of cheating, and that it would be more beneficial for my flying in the long run to be familiar with all the subjects.