I've ridden in a few cars with KW... they handle a bit better, but I can't really attest to ride since I've spent the most time in my car with the D2's. My car is almost as low as possible on the D2's in front with no modification, the rear of my car has shorter springs, which in turn, still allow me enough thread to crank them down until the fender sits on the outside of the tire.
It's really just annoying because when theres salt on the road, you head every bit of it bouncing around the inside of the fender, my plan is to install the back half of the fender liner, it will still allow me to clear the tires, but block stuff from being thrown into the inside of the fender and making noise. The only other issue is without fender liners, all dirt and stuff get thrown backwards and it ends up dirtying up the front of the front door jambs. For a while I couldnt figure out how dirt was getting in there until I realized that it was because of the lack of fender liners.