I obtained PMP credential on 20th March 2013 (Mumbai, India).
Result was mix of Proficient and Moderately Proficient. I didn’t get any Low score in results.
Preparation done for 2.5 months, during late nights and weekends. Though I didn’t study everyday and all weekends. Total preparation time was approx. 160 hrs.
Which included:
1. PMBOK4: 3 times + 1 quick refresh. Memorized T&T only (tried to understand Input & Output but didn’t memorize them).
2. Headfirst Labs Critical Path drill pdf.
3. Headfirst Labs – All Tests
4. Oliver Lehmann – 75 qn Test
5. PMstudy – 4 paid test
6. Simplilearn – 4 paid test

The questions in main PMP test was very different from mock tests. Mock test enable you to think in the required direction which helps during the main test.

Honestly I didn’t score 80%+ in any of the test, as all the websites/folks recommend as a prerequisite.
PMStudy Scores:-
* Test1 – 60% , Took Re-Test1 – 73%
* Test2 – 64%, Took Re-Test2 - 86.29%
* Test3 - 67%
* Test4 - 66%

Simplilearn Scores:-
* Test1 – 66%, Test2 – 71%, Test3 - 69%, Test4 – 73%

PMSTudy test, HeadFristlabs, PMZilla and Oliver Lehmann were the best ones for me to learn.

Disclaimer: This is an individual’s experience, and should not be benchmarked for obtaining PMP credentials.