Wow, how do you define "bowling through defenders"?
If you mean giving LB's a stiffarm and putting them on their a$$, or if you mean gaining extra yards after the first hit, or if you mean ability to get the tough yards in short distance or goal line situations, ahhhhhh, I think we'll be "OK" with Willis.
Actually, Willis has already convinced me that he far surpasses TH in all of these categories.