RE: Handling at high speed
I have the F1 goodyear supercar tires. The srt handles great, the problem I found at high speed is the tires tend to track the grooves worn in the road from big trucks. This sort of gives you an uncomfortable feeling. That is probably what your feeling. I believe it is tire grip and down force causing the car to track the grooves like it does. High speed should be attempted on a good road that is safe to do so or a track.