PR is one of many factors Google uses in evaluating a webpage. No one on this forum knows for sure how much (or how little) it factors into your webpages' rankings. Opinions are many; hard facts are pretty much unknown outside of those Google employees who know the algorithm. It is absolutely true that in many cases of SERPs, lower-PR webpages might outrank higher-PR pages. In my personal experience and observations, this is usually because of other SEO factors in the higher-SERPs webpages. For example, a PR2 page may have the search term in its URL and/or in its title and may outrank a similar PR4 page that does not have the search term in its URL or its title. So again, PR is a factor that is somewhere between "useless" and of massive importance. It is definitely not "useless", and it is definitely not the defining factor of a successful website. It is simply a factor, and therefore should be just one part of an overall website strategy and evaluation.