I signed up for paid access before they launched, and it is worth every penny.
Perhaps because it's subscriber-only, illustrators on PACT feel free to state exactly what they got paid by different companies, what the usage terms were, how quickly they got paid, etc. And that information is not readily available anywhere else AFAIK -- lord knows I've looked. It's really a game-changing site.
Plus you're getting the info directly from some big name illustrators, which lends credibility to the entire endeavor.