I played the PS3 version last night and the improvments over the original are great. The handling of the vehicles feels much better than before, you really get the feel of the wheels being slightly sunk in the gravel and the other cars tracks having an effect on handling. The graphics looks great, even at just 720p and the UI is great and very well presented. It's also got the GRID flash back system, which is good.
The two american rally drivers in the game do make some stupid, half ars*d comments during races that might get on your nerves after a while. But on the whole I am really looking forward to this.
Going to try it with the G25 today.