Played this a while ago on the Vive but with no horizon lock and basic graphics, I preferred Assetto. But this has now been added as well antialiasing and in-game supersampling (via a beta patch).
But most importantly they have made it work with Pimax, no PP required! Their patch notes specifically mention Pimax, a few times.
With all settings max, 8x antialiasing, 150 supersampling I am getting a smooth 70 to 80 FPS without motion smoothing. PiTool is at 1, Steamvr I think is 30% and application specific set at 100%. And it looks sharp and clear and drives brilliantly. I am really pleasantly surprised. A big graphics update looks to be in the works, I just hope it does kill performance! The beauty of this is how smooth it is.
Anyway, there is a free time unlimited demo, if you are in to VR racing, it’s worth a look.