I sometimes wonder whether some aids are there to help lesser drivers and maybe DS3 users or are just gimmicks. It would be interesting to at some point hear from people, who have used both the DS3 and a wheel, about the effects of aids other than TCS and ABS.
+1 on mentioning the DS3/Sixaxis users. I use the Sixaxis and I would also like to see a comparison between using a Sixaxis vs. a steering wheel.
I don't use ASM ever. It slows the car down too much.
I use only the amount of Traction Control and ABS that I need to drive the car properly. I like high ABS so I can brake and turn at the same time. Traction control on 1 is sufficient for 90% of the cars in the game.
If the car is too hard to control even with TCS up around 5 or 6, Skid Recovery is applied post haste and yes, I can get better times with it, but not even close to the better steering wheel drivers.
I hate Active Steering because it jerks the car in the opposite direction I'm trying to go. I don't see myself ever getting used to it, so it's always off.
The driving line is useless to me. I used it at the beginning, but noticed that it is based on the speed of the car, not the car's abilities. Some cars brake better/worse and renders the braking points useless. Finding your own braking points for each car is better than losing time in a corner because you applied the brake sooner or later than you should have... just because the red told you to.
Cheats? I don't consider any of them cheats. They are there if you need them, but try to find the best match for your abilities/controller/steering wheel that you are using.