Ok guys, I'm confused.
Why do any of you care what Google reports in their backlink check since it's not actually showing all the pages that link to you, and it doesn't actually effect your rankings when it changes?
Is it just cuz you're bored? You think it means something? If you think it means something, what exactly might that be?
It provides a nice idea of the number of quality websites linking back to me. This does mean something to me. As related to PR, I have certainly noticed that all things being equal - my websites generally have higher listings when the PR is improved.
I have a site that has had virtually identical structure and pretty consistent content (brochure site, the content in this case doesnt change much). I've focused all SEO efforts for it lately on linking and noticed that when my PR moved up a notch or two, so did my rankings.
Certainly there's something to be said for having Google showing more links back to you. I understand and very much agree that its by no means comprehensive. For a while I thought it simply showed all PR4 or higher sites, but now I've let that go too. I will say though, that its still a nice measure of what Google sees linking back to you, and therefore has some value. Its give me an idea of how effective my linking strategy has been lately.
In my experience, the majority of the sites it excludes and does not show have been low PR and/or the lesser valuable links coming in to my sites. Thus, I will continue to use Google as a nice measure of my sites' progress in obtaining more and more valuable inbound links.