Overall: I think the studying and exam has a been a very worthwhile process. I took me 2 months from the day I joined PMI and purchased study materials to the day I passed my exam on my first try. I was not working at the time so I was able to apply ~250 hours to this effort. If you want to pass the exam with a solid score then I definitely recommend putting in the study time to learn the terminology, processes, etc., even if you have many years of PM experience.
The application: Keep in mind you only have 500 character (not 500 words) to document your experience. Also, I agree with those who say to use PMBOK terminology when documenting experience. I can see a big improvement in the description that I wrote after I read the PMBOK vs the one I wrote before. I was not audited.
Using the PM PrepCast: I recommend this material. I found it effective to listen to the audio, take notes then follow-up by reading the corresponding PMBOK sections. The lengthy interviews and some other sections were well suited to listening while driving or exercising. The software made me wait 2 weeks from the purchase date until I could take the test to earn the credits but I waited longer so I could complete all the materials first. I probably should have taken that test much sooner so I could have moved my PMP application ahead more quickly, then finished the less critical audio files later.
I read the PMBOK twice, used PM PrepCast with 650 exam questions, took 1,100 additional free on-line exam questions then 1,000 PM PrepCast exam simulator questions. I felt confident going into the exam and did fairly well on the exam (3 areas of proficiency and 2 areas of mostly proficient).
Scheduling the exam: There are plenty of testing sites near me so I preferred to wait until I felt ready to take the exam before I actually scheduled it. I did not want to commit to a date hoping I would be ready. I could have schedule with about 1 week lead time but took the 2 week lead in order to get a location closer to home. It was much easier to scout the location and closer to home in case of poor (snowy) weather.
The brain dump. I expected to use some of the pre-test 15 minute tutorial for the brain dump but when I arrived at the test site I was told I could not start writing until I actually started the test. My brain dump took 28 minutes and I started out slowly for the first 75-100 questions but I was able to pick up the pace and finish with 8 minutes to go. My brain dump included: the process group names/numbers and knowledge areas chart , ETC, EAC, PERT, sigma, EV and other formulas, 7QP tools, plus I/O process numbers for work performance data-info-reports, change log, issue log, stakeholder register, risk register and a visual drawing of a FW/BW pass.
Going into the exam I planned to write down the number/description of the questions where I was uncertain so I would not have to scroll through a bunch of marked questions if I wanted to quickly find a specific question. However, I also planned to not revisit questions w/o a strong reason to do so. I only marked/revisited 1 question and went with my first answer on all the others. This worked out well and helped me avoid a last minute flurry of changes or self-doubt.
Good luck, I hope this info helps!