Are you having any trouble with snap-back in the steering wheel? I've tried every setting imaginable and most of the time if I let an RR or MR car step-out even a little bit off-throttle and begin to counter-steer I'll get a sudden snap-back in the steering wheel. This happens with my T500 and my G25. I've been trying to work on it in the Ruf's and Tire Physics" thread, but looking at your lap I see you get off-throttle a few times just a bit more than you probably intended but you are able to counter-steer without too much difficulty. This is the natural way I drive rear-weight-biased cars both IRL and in sims, so it's really bothering me that I'm unable to do it very well in GT6. (On occasion it's OK, but it's rare; mostly I just avoid letting the rears step out enough that I have to counter-steer.) I generally drive with no aids.
Are you referring to something like a tank-slapper? Where the car snap oversteers in the opposite direction you intended? Or is it actually the FFB in the wheel turning back straight?
I never use unrealistic driving aids, the most i ever use is ABS on cars that actually have ABS in real life, but even with those cars i sometimes like to drive without anything just to practice my braking. In the Stratos video i have no aids at all, not even ABS, i even have the realistic grip loss turned on, there's also nothing adjustable in the setup of that car since it's all standard, so it's nothing to do with the setup. I own the normal Stratos from the dealership as well and there's no noticeable difference between that and the AE version, if anything the AE version is more twitchy because it has a bit more power.
I'm honestly not experienced enough to really explain what i'm doing with the Stratos, but it's almost exactly the same reactions i give to a kart. I think the main thing to remember is that if you wait even the slightest before allowing the wheel to counter-steer, then you'll either have massive oversteer or even a spin, you have to let the car tell you what needs to be done and with a simulator it's much more difficult to feel what the car is doing compared to real life. That said, a lot of drivers (even professionals) try to take control of a car and try to force it to behave how they want rather than working together with the car and allowing it to show you how it behaves, i know that sounds very philosophical, but if you just learn to listen to what the feedback is telling you, then it's almost subconscious. In my video, all of those little twitchy maneuvers i'm making with the wheel is entirely based on what the cars feedback is telling me to do, i almost don't even have to think about it, i know when the car is starting to oversteer before my eyes can even register it and in a car like the Stratos, that's something that you really need, especially in a sim where there's no other useful feedback on your body. I suspect in real life that you're relying on the g-forces on your body and your inner ear senses more than you think, which is why you might have problems with a static simulator, this is actually a fairly common thing among real racing drivers, that and motion sickness.
All i can suggest is to turn the steering strength up to max and just let the wheel do all the work, if you're using the T500, then PD has adjusted the levels so that even at 10, there's no clipping. You also should remember that the steering ratios for probably every car in GT6 is lower than in real life, so everything is just more sensitive. I have my sensitivity at -2, but it's still not enough, when i first started playing i was over correcting often because of this, but i learned to deal with it fairly quickly. The FFB in GT6 is so good that even though the cars are technically more difficult to drive, i can drive the same cars easier than i could in GT5.