Shanahan by a landslide.
Holmgren is one of the most overrated play callers ever. He had absolutely no creativity...if it weren't for the pure talents of Rice and Taylor, his offenses would've been dead. The biggest problem was his lack of sophistication in the red zone. He couldn't figure out how to get it into the endzone...it was all up to Rice/Taylor taking it the distance, deep or short, or winning one on one battles in the red zone.
You want to develop a boring offense, you hire Mike Holmgren. It was very basic stuff and only the personnel can carry it.
Shanahan, conversely, had a million ways to finish drives.
[ Edited by 1For13On3rdDown on Oct 29, 2012 at 6:17 PM ]