Do you have a dead zone in your steering?
When driving straight, my steering seems to have a bit of a dead zone, where you can turn the steering wheel and the tires will not respond. on the highway I can swing the wheel back/forth for about 2 total inches of play, where the wheels don't respond. I have driven a couple other vehicles on the highway recently, and they seemed to immediately respond immediately when turning the wheel. How is your steering feedback on the highway?