It's probably the best mix of simulation & tracks & cars that is currently out there, in my opinion. The force feedback and the handling are lacking compared to Assetto Corsa, but the vehicle range and track range I would say compensates for that. Then again, Project Cars 1 development and DLCs might be finished, the way I see it, while Assetto Corsa continues to bring new content.
Sometimes it can be glitchy, and usually a patch fixes one bug and introduces another. That's quite annoying. Nevertheless, a nice experience, and a pleasure for me to drive, especially in online multiplayer. I remember trying career at some point, but I found it incredibly boring and never touched it since.