Yeah GT is good on the customizing front. in terms of gt5
You can upgrade all the parts on the car which increases performance but opens up more tuning options.
with all the right parts you can tune each gear individual plus the overall gear range.
Suspension ride height, camber, toe, (the older versions had caster adjuster too), spring rates, damper settings, roll bar.
You can tune your LSD deceleration and acceleration (well you can on gt4)
Aero settings for wings etc on certain cars.
TC
ABS
I cant remember what you can tune on gt5 I haven't played it for a long time.
But you can tune a pretty big range of things in GT games.
Forza I haven't played but I am highly highly impressed with their next gen console and the new game. They use a system which essentially creates a you as a AI driver, it takes your driving traits and creates a AI drivers based on these, these drivers are than used against others in other games, so where most games give AI drivers braking markers and are designed with a certain algorithm in where it becomes predictable the new system means you essential race real gamers so the braking markers are all different, and each racers style is different, there is no predictability and as drivers change their style so does their AI. There have been some claims the AI is more aggressive but it makes the driving much more realistic for gamers. One of the people behind the game said the game learns as it goes so you will find cars will start showing there noses and taking different lines without the producers even writing it into the system. (It was on one of those gaming tv shows)
This of course means you need to connect to the cloud to initial the up and down loading for the system. but its very impressive that the AI are now real drivers so the level of realism should be very impressive.
It sounds like a big step forward for gaming and really eliminates the old predicable code written AI with realistic drivers.
