I passed PMP today. My sample test scores were the following. 

 

Oliver 175 - 82%

Head First - 80%

SimpliLearn - 80% (Oliver rates this hard)

PM Prep Simulator (Free) - 76%

PM Study (Free) - 86%

 

4 weeks studying + 2 weeks tests/closing gaps. I read PMBOK (most of the chapters) once, Rita once. I did take lot of sample questions (Rita, Scordo and ton referenced by Oliver on his website). Including full tests mentioned above - I might have taken around 2500+ questions.