I know what you mean by your post but I can't resist being a smart ass... A lack of torque will make you keep your foot in it day in and day out
Thought this was a pretty interesting article. Apparently the output is underrated: http://blogs.insideline.com/straightline/2010/03/inside-line-dyno-tests-the-2011-ford-mustang-gt-50.html
Nothing new, the older 4th gen Camaros were very underrated too. They would put down nearly what they were rated at. Chevy does this to keep the rating away from the Vette, Ford to keep it away from the GT500.