Thanks for posting. I am debating getting the PA4 for this winter and there are very little reviews out there.
I have 3 bald + 1 almost new PA3 on my winter wheels (due to a puncture). My dilema: get 3 PA3s or 4 PA4s? So in my case upgrading to PA4s would be a non-negligeable price difference. If the performance is that much better, I am willing to do the move. So I welcome all info on the PA4