ive played the forza 4 demo at a mates house and it barely seems different to forza 3
at home i have ps3 with gt5. If gt5 was to sort out the tuning properly i.e engine changes, turbo/supercharger swaps for ANY car and brakes, and then change standard cars to premium, itd own forza hands down imo (this is just from playing forza 3 and forza 4 demo)
Forza is more for people who wanna tune their cars up to the max and piss about with loads of mates online
GT5 isnt about modifying cars at all, its just about driving them... nothing else. Its purely and simply a drivers game
Fuckloads of people dont like gt5's handling as its "unrealistic" and "forza's alot better" .........its gonna be years and years until they can make a game thats as close to real driving as possible
Both good games tbh, it just depends what you wanna get out of the game