I would say Willis rushing for 120 yards mainly because that means that we were moving the ball successfully through the air and on the ground. Not to mention, with Willis' runs, we would be chewing up plenty of clock which would take the pressure off of our defense, and not allow Grossman to play with these balls that he apparently found since last season.
But once again, it would not be labeled as a victory for the Bills by the media, but instead as a number of screw ups and miscommunications by the Bears, no matter how perfectly plays/schemes were executed by the Bills.