Passed the PMP today (Singapore).  Here are my LL:

1.  PMBOK Guide study (unnecessary)

2. Rita Guide (amazing) I used 7th, but 6th should be fine

3.  Do as many exam preps as you can!

4.  Oliver Lehman 175 (v2.5) is excellent and the same difficulty as the real exam

5.  The exam is not so much about knowledge of the PMBOK, it is about understanding the wording of the questions.  Rita's book provides excellent insight to that.  Whilst I did not receive any 'exact' question matches from the prep exams (Headfirst, Oliver, Rita) they do serve as perfect revision to understand the confusing wording used in the questions.  There is a lot of distracting information in the questions, you need to filter that out to choose the right answer.

6.  Very few calculations (1 decision tree, 4 EV, 2 Critical Path)

7.  Practicing dumping all the formulas onto one page, so that you can 'dump' when given the scratch paper is recommended.

8. 90% of the questions 'situational'.

9.  ITTO memorisation unnecessary, just understand what the process does and you can work it out.

10.  Do as many exams as possible!!

Scores:

Initiation - Proficient

Planning - Moderately Proficient

Executing - Moderately Proficient

M&C - Moderately Proficient

Closing - Moderately Proficient