Then you`ll probably like it, I guess. A couple of the guys I race in a rFactor league say they are having fun with it as a time killer now and then. Quick game there is for sure. I only tried it for about 30 minutes, as it was bundled with a graphics card i bought.
I am really "nazi" when it comes to racing games, they have to be hardcore. No driving aids and lots of settings to adjust.
What I CAN say about DIRT, is that it has nice graphics (the bloom is overdone, but ptobably moddable) and great crash modelling.