Hi I agree that the PMI exam practice is quite frustrating. I have done four of Prepcast mock exams so far. and most of it i can understand the explanation which is usually very detailed. even if i dont agree with the answer, i can at least understand how it was being arrived. The PMI exam seems to look a little different for some people. In my case, if i get it wrong, it does not highlight what is the correct answer. and the explanation is just vague and gives me no clue sometimes. And it being this unclear, and it pops out immediately to tell you if you are right or wrong immediately on submit is not helpful. because it frustrates me everytime i dont understand why my answer is wrong, the explanation is not clear, and i cannot deduce what is the right answer.
I kind of gave up on doing the PMI questions for now. I might go back to it after i have finished prepcast, if i still have time. my gut feel is, most people dont get the PMI practise exams before they launched it, so i dont think it is a dealbreaker if you dont do it