I have both on PS4Pro, and PC
If you're on PC, then AC is definitely worth it. Despite its dated, yet functional graphics I think the sense of speed is superior to PC2, not to mention the sublime FFB, and general playability out of the box. I bought it on release on both Steam, and PSN, yet haven't touched it until last spring. I was turned off by its graphics tbh, however, when much much later I gave it an honest try, I fell for its physics, track detail (did I mention the sense of speed?), and general feel of cars. Doesn't hurt that you can get it for a song on Steam these days.
On PS4Pro I think PC2 has the edge. Better graphics, and solid 60fps with full grids. While, again, physics are superior on AC I cannot stand the micro stuttering, and slowdowns even on a Pro.
