I think I would take Mullen. I think his spread style which incorporates the run is better suited for the SEC, and he's a little younger, which I think might appeal to recruits more.
Not trying to pick a fight here, but Mike Leach's Big 12 South resume looks like David Cutcliffe's, Ed Orgeron, and Sly Croom's combined.what he's done in the Big 12 South is pretty impressive