Some excellent features and looks, along with some disappointing ones.
I play GTR2,GTLegends,Race,RFactor,etc. I use a simple but effective Logitech Momo steering wheel/pedal setup. I play on a AMD Athlon64X2 @2.7ghz, 2gb RAM, 8800GTX OC, 1kW PS, WindowXP Pro. I play DiRT at 1280x1024, Graphical Settings high/ultra except- Shadows on medium,G-Card controlled 16xQ AA. I havent completed the game yet either. After first driving a few miles in Time Trail, tweaking the controls to get a proper 'feel', i dove into my first Career event - a single car point-to-point classic rally with the fwd Renault Clio and i was HOOKED....it looks Incredible.It ran with a great framerate with NO stutters(bless the 8800) the particle effects are great(love watching the cars get really dirty) and the car damage model is very nice. The car interiors and driver models are mostly accurate and awesome looking as well. A drawback I instantly noticed switching through the different viewing perspectives is that on the secondary cockpit view (seeing further back) there is a horrible animation delay when you go to shift and then a half-second later see your animited virtual arm go to shift. He also moves just too slow which if for if some reason you have to rapidly shift down through the gears(and you'll have to:)) the leisurely shifitng animations backup and 5 seconds after you completed your last literal shift, your driver model finally finishes the animation sequence. No Good. Same problem if you go to yank on the Handbrake(and you'll need to:)) In other race-sim games they have the animations and physical inputs synch up much better and 'smarter'. I use the first cockpit view (close to wheel, best in my opinion,most-'sim') so you don't really have to see it. The problem with that view is their is no option to turn on indicators (too sim?) and it would be nice to see a speed readout or a selected gear indicator. Some cars cockpit layouts let you see a rpm meter/gear indicator in that view, some don't.
The cars feel good physics-wise, but i never drove a 2000lbs, Rally-Spec(read "very snappy")1.6L Turbo rally-tuned FWD Dirt Rat through some nasty swamp-wood so i cant really say if there "realistic". They are fun to drive after tweaking the controls and understanding what they want you to do Tuning-wise for each layout. After some time i was pulling off some very nice sliding that looked brilliant in the replays. The courses are varied terrain-wise and great to race on and great to look at. The level of immersion is very high. Sound is great, but seems to make a larger than normal impact on performance than most games when set to d3d-type.
I was still very pleased on first impressions and then i went to race a multiple vehicle event and instantly got the momentum knocked out of my sails. Much lower frame rates(compared to single/dual car events) and the occasional stuttering make the mulitvehicle/multiplayer events mostly unplayable for me. When the cars cluster together things can go into the low 20'fps.
I benchmark a 10000+ in 3dMark06 with my rig so make your perfomance decisions based on that. Im pretty picky about framerate some people can play racing games at 30fps or sub-30fps, i cant. The Single car events and dual car Crossover events run much better so i just play them. I basically only play 75 percent of the game(should have payed 29.99 instead of 39.99), eschewing the 3+ vehicle events just cause of the doggy framerate issues. DiRT is a really good game that looks amazing, but the bad taste of its quirks are hard to wash away.