I dont have enough words of praise for cornelius fichtner and his Team, This website is awesome right from folks sharing their experiences to the Lessons Learned Threads.
The Prepcast Simulator is a guide to success , I dont have much to share , RITA/PMBOK 3 times and The Simulator helped me suceed as suggested by our PMP Community here
Also I Didnt really take any timed quiz and took the prepcast exam simulator directly , never got more than 70% , Worked on the gaps, One another source that helps us is Edward Chung .