dirtydog said:
Not much

I think the only way it is really an improvement over Forza is the framerate.
Dirty Dog
Listen, try and take some of this in...
The point im making regarding the cars is that GT series focus's on making the cars the main interest in graphical quality/terms.
Forza 2 has some fantastic detail in roadside features, its got much more varied tarmac and road surfaces too. Its obvious to me that for example GT HD uses a lot more polys on their cars, and in every other way FM2 looks better, tarmac, shadows, roadside, spectators and its whole enviroment is much better looking.
Many seem to forget that GTHD which they use as a way of comparing each game or even systems and how flawed that is because when the PS3 has to deal with at least 7x AI cars and their physics then system resources will be a lot more stretched than they were in GT HD using a single car.
Of course you being the expert it wont be a problem for Polyphony as the programming or level of talent at turn 10 sucks doesnt it as noted in your previous comments.
The most important factor for any racing game is handling and what fun it can give. After extensive playing ive got onto the handling and learned the track (something of different skill required for each car) and personally i cant wait to race against real people or at least see the AI in Professional setting.
Jaggies aside the game looks great, the damage, the particles of dust and smoke, the audio is easily the best of any racing game bar perhaps GTR that ive witnessed and as an allround racing package and entertaining game well for me im happy with it.
Your welcome to come here and try it in 1080p on my projector, racing seat and wheel with 7.1 audio. Its a big step up over Forza 1, for hevens sake its HD for starters which is so much crisper looking.