I played quite a bit of Project Cars (Pee Cars), and from what I understand the physics, AI and other aspects of the game were vastly improved with time after release. They also vary in quality from car to car. I would agree they are not even close to what RF2 is (especially with the URD mod), and requires a ton of FFB setting tweaking to even get it reasonable. Still, once I figured it out I had a bunch of fun with the game. It's definitely more of a sim than an arcade or console style game, and the AI is among the best out there. The career mode, while a bit thin was still pretty fun.
Excited to see what they do with Pee Cars 2, the car and track list looks pretty awesome.