PR Toolbar and Link Building

[Industry]

How much should we trust the PR we see in the toolbar? Just as a guide? And why does it vary so much for pages that are on the same level of the site with no obvious difference in direct links to those pages? How can Sub page A off the home page be a PR3 and sub page b off the home page be a 0?

[SEOPTI]

If sub page b is filtered out (dup content) or a link page, no semantic just links, this page will have PR0. With Noindex,follow it will also be a PR0 URL. There are many examples.

[Industry]

It would be more the case of Sub page b, c, d, and e being fairly equal yet wildly differnt for the TBPR.