Is it style or substance that wins a presidential debate?

Apparently President Obama did not take into account what professional athletes do: the need to arrive in the mile-high city a day or so early before a match in order to be in top form.  Mitt Romney did arrive early and spewed out his memorized PowerPoint presentation perfectly (without the screen), full of so many detailed claims misrepresenting his previous positions that the two-minute response format left little room for a coherent response.

Many felt his aggressive style was impressive, even presidential.  I found it obnoxious.  Robert Shrum thinks Romney won the debate on the strength of his "performance art" although he catalogs a number of ways in which Obama won on substance.

I do agree with Schrum, however, that it would have been nice if the President could have been sharper in making some of his points, although I'm not sure if short quips come natural to him.  For example...

The Republicans ask whether Americans want another four years like the last years. Obama could have asked: Do you want another eight years like the Bush-Cheney years—because Governor Romney has the same policies and the same advisers? 

                                   --  Romney Won the Debate but it Was No Game Changer