I had issues with my wheel at first also. Several times it seemed that there was a severe lag in the steering and/or brake response. Result I would come up to a corner apply brake and not slow then turn wheel and not steer. The steering would take hold but after a delay, same with the brake and I would be blowing through the corner more often than not.
In my case the problem turned out to be that I had plugged the wheel into a USB 3 port. I switched it to a USB 2 port and it worked fine since. I thought it was odd that it would do that and the reason I figured it out was that I tried to reload the firmware and that would not work until I switched it to the USB 2 port.
So check and make sure that you are plugged into a USB 2 port and not a USB 3 port. If that is not the issue then I have no clue.