I have to say I'm not really feeling these big physics improvements at all. Aside from a few minor details and subtle differences you could easily be fooled into thinking you were playing GT5, a difference in feel you could attribute to a small patch or even just a new version of a car model.
Also coming over from GT5 is the clutch/gear system that doesn't work properly, meaning you can't drive it like a real car. Another thing it takes over from GT5 is the fact that the car is undrivable without ABS-1, touching the brake with the ABS turned off is like pulling on your handbrake. Perhaps it is drivable but it definitely isn't realistic and it is exactly how GT5 behaved.
I'm also annoyed that there still isn't a brake deadzone adjustement, my brake pedal (G27) has a slight rub issue, which with GT5/GT6 is a massive problem because of how unrealistically oversensitive the brakes are combined with the lack of any deadzone adjustment. In other sims the brake isn't so sensitive (like real cars!) so It is rare that I even need to bother with the deadzone.
Altogether I'm a bit disapointed, sure the animation and chassis movement looks more realistic, and in some cases the graphics are improved (but lower FPS than GT5) but when it comes to driving it just feels like a slight tweak compared to GT5 rather than some big move in the right direction.
Ultimately all of the basic issues with GT5 remain here.