This is a good topic. I really feel that the ps is a vital part of the application process, b/c up until the interview, that is the only personal contact that the school has with you, and, at least I feel that it was one of the most important aspects of helping me to get and interview, esp. at osteo schools. This is b/c these schools really place an emphasis on being an extremely well rounded applicant. So, that said, it is definitely worth the time to make sure you do the ps well. My undergrad school had a health professions advising office, and I became good friends with the head of the office. We revised my ps a total of six times, but it turned out to be very good. Your use of verbage, and how concise your sentence stucture is really important, esp. on the osteopathic application, b/c I think the maximum # of words is 325. So you need to be very concise. Hope that this helped.