I like seeing former Hawks come back as much as the next guy, but I don't think of the Cincinnati or ND defenses he's coached as being anything special.
"He coached on the Virgina staff for 3 seasons and was promoted to defensive coordinator after the ’08 season, but left before he fully took over the job to take the defensive coordinator position at Cincinnati, under his old boss. In 2009, Diaco had a tall task ahead of him when he had to replace all but one starter on defense. The task did not prove too tall however, as the Bearcats finished 3rd in the country in tackles-for-loss. He was one of the many reasons that the Bearcats went undefeated through the regular season on their way to a Big East Championship."