It's not mutually exclusive. Speed puts a tremendous amount of pressure on the opposing defense. They have to account for each and every play. In a game where big plays make a difference, you absolutely need to have good players with great speed.
Agreed, but raw foot speed alone without the other 500 intangibles that make for good players mean nothing, if all you have is the former. Case in point, Davon Johnson and Kendal Thompkins could probably match up raw speed-wise with a lot of the top WRs in the country. Travis Benjamin might pull a DVD at the combine and put up the best 40 time out of everyone. But so what?
I think its wise, if you are at a school like Miami, to augment speed with the grit.
Miami was always a school at the forefront of innovation in college football nationally.
The fast sideline-to-sideline linebackers to counter the option...the Air Express and the Bomb Squad...these were things "before their time"...at least nationally.
When UF was winning with Meyer with his Wing Tebow with speed at the skill spots with that offense...it is something I could have always seen Miami going with, because its that next step in the evolution of college football combining that speed available with some of the old school grit and a really good defense with a mix of nasty, skill, and guys with a chip on their shoulder.
Guys like Thompkins and Johnson...who knows what they would have been with good coaching early on...I don't know either. But good coaches, nationally, can meld all of these player types into national champions...happens every year.