Here is my proof that PR DOES make a BIG difference. The very day that my PR went from PR2 to PR3, I had a huge spike in traffic, have a look at September 29th
my month old site hit a PR3 i was in shock when i was told by a DP member, PR3 is great for a site that is one month old. my other sites stayed the same,and one dropped
Wow, I have made several new sites recently. Most are still PR0 but one has gone to PR2 even though it is only 2 pages! Also another has gone to PR1 even though I ignore it.....strange! And I have some very high quality sites, updated often, still on PR0 I think this just goes to show how inaccurate Google's algorithm is......