We have been observing both PR and PA/DA of different domains and their sub pages and have realized that page/domain authority is a much better way to judge the quality of a site. If you want to judge a websites overall quality, then just install seo moz tool bar and by just looking at the domain authority and page authority of a site, you can get a fair idea about its overall standard. That, however, is not the case with page rank. We have seen many domains with high PR which do not have a single quality backlink and they have still been able to maintain their PR for over a year. This does not happen with PA/DA. If the site becomes inactive or deteriorates in quality, then its overall domain and page authority will be reflected in a few months. So overall, PA/DA has much more significance then PR. Pls share your views as well.
PR has more or less gone into irrelevance. It's a meaningless number that is easy to manipulate. (As you've seen with these high PR domains with no backlinks - simply a well-timed redirect will do the trick.) DA/PA has a bit more meaning, but don't rely just upon numbers and research, as a high DA/PA can be obtained through manipulation, too. I've seen it happen with hidden links, for example, or the website might have a lot of spammy backlinks. So, investigation would highlight issues such as these.
You should check out majesticseo. You'll get a much better analysis on the balance of high quality links.. I'm able to outrank my competitors every single time thanks to their visual graph for citation flow, trust flow, referring domain, & external links. To Your Success, Marc