I'm waiting for Forza also, but I doubt it will top GT4 in all areas (although I'm hoping).
GT4 AI makes mistakes also, just watch in B-spec mode and you'll see your computer driver (and the others) make some miscalculations.
Yesterday I was racing a Family Cup (A-spec) on the Seatle Circuit (it's a good way to build A-spec points). I was using my Camaro LM car with the difficulty set a +6 which was giving me about 100-120 A-spec points for the 2 lap race. Coming to the chicane before the finish line I took a rather "cheap" inside line (I basicly straightlined it to try and pass). The compters GT40 bumped me on the outside, then corrected, almost hit the outside wall, then corrected, and proceeded to lock up his brakes and hit the wall on the other side of the chicane. It was so funny seeing this car go out of control right in front of me. After that it was an easy pass and I won the race. :-D
@X-ray
98.5%. Only a few driving missions left. So far it's been a great experience. I noticed today that the "secret" black cars were back in the used car lots, so I guess I've been playing for the equivilent 4 years now. :lol: