Good updates PR constantly however changes pushed out to the toolbar are not as frequent. And you don't know what the latest visible change is in a response to...just pointing out the obvious here, don't get so hung up on pagerank, especially the pagerank pushed out to the toolbar. There are better ways to measure success/failure.
If you're looking to make any money from links, look for a pr 5 (or preferably higher). Most people tell me that "PR 4 is the new PR 0". With so many directories and high PR blogs out there, it's VERY easy to get a PR 4, and still pretty easy to get a PR 5. If you don't think you'll have a PR 5, I wouldn't even worry about it. Also, if you're having to work hard to get a PR 2/3, I'd say you're not working very effectively. This isn't meant to slam anyone, it's just that 1 or 2 links from a PR 5 should give you a PR 3. How hard can it be to get 1 or 2 links from a PR5 site? PR 6+ is where real $$$ can be made with links, reviews, payperpost, etc. If you think you're close, then I can certainly understand why you're anxiously awaiting the PR update