Finally I've got to play the game. My first impressions follow.
After downloading it (Steam), I tried to launch it. My Live account was somehow put on hold and couldn't use it. After some SMS' fo and back, I got it back. So I launch the game and it appears in window mode and full of dudebro attitude. I start configurating graphics, using the benchmark tool and finally set everything to High, to get something close to 60fps on average. I set my DFGT and was glad to find it is recognized and had to configure nothing.
So I stop there and go for lunch. When I get back to have some rally time, Dirt 3 doesn't launch. I verify cache and it doesn't launch. It appears on the task manager, but not in applications. No matter what, the game won't launch. So I go to the folder where it's installed and I try to launch from there. And it works! Dudebro greets me again and after more videos and menus that I can remember, I finally can drive my car! And it drives well. I'm surprised by the weight of the car, the good feedback and correct handling. It's not a sim, but it's sim enough for me. Rally track is nice, graphics are nice (if artificial) and sound is nice. So once I'm behind the wheel, everything is sweet. It shouldn't have taken this long. So finally after finishing the rally I quit and get some rest.
Some hours later I go back to play some more. It doesn't launch from Steam, as expected, but this time it doesn't launch from the folder either. I try a second time and nothing. I try a third time (yes, I want me some rally more!) and finally it launches. I play the second rally and when I finish it I go back to the first to beat my former 4th place (and I do it!). Now I have to play some circuit with some other cars and a head to head. I don't understand why, I want to rally. I want to race in a long rally championship.
Anyway, now I'm redownloading the game from Steam, hoping it will work correctly this time.
In conclusion: the time I've spent racing in a rally track, it's been a great experience. Everything else ranges from uninteresting to upsetting.