Well... If you compare AC with only PC hard-core driving sims available today, yes, it's good.
The problem of this agreement is graphics is just made of polys, textures and stuff like that. It has nothing to do with what we call "physics" of a racing game/sim. Instead of comparing sims to sims we can also (and should?) compare a sim racing title to whatever racing games out there, be it PCARS or NFS. Even if we cross the border of genres and compare a RCG to a FPS, it's still textured polys with some effects. Graphics programmers working for different genres may face slightly different problems, but the underlying tech is basicly the same. Actually you can race cars in BF3 or Crysis 2 if you want to. Don't expect any realistic physics though.