What I used: Mike Griffiths Exam Prep (Green) Book + Prepcast Exam Simulator.
Exam Simulator experience : I was failing the Exam Simulator , on all takes I was scoring 50-60% with Domain II as my lowest (that's the % on the ACP ). This is on both the Quizzes and the Premium Exams. So 2 days before my exam I spent a lot of time trying to read through the detailed results and understanding why I kept failing. The detailed explanation gives you tips on how to approach the problem. It gives you insight on how to eliminate 2 potential wrong answers and then choosing the "BEST" answer from the other 2 left. When there are points I don't understand even after the explanation I refer to the footnote where they indicate the reference, those were quite helpful too. A night before my actual exam I tried to do one last Mock Exam (Exam 4) I passed It within Target on all domains.
Results: Passed the PMI ACP today with Above Target on all Domains
Feedback: The Simulator Exam trains your brain to have the right mindset when you take your actual exam. If you're observant enough , you'd notice that some of the exam questions are similar to the mock only given in a different perspective or situation.
Tip: Practice. Practice. Practice using the Exam Simulator. then Fail. Read why you got the questions wrong. Then go Practice some more