Mason might have done very well at OSU, because I think post John Cooper, Ohio State had much better talent relative to the Big Ten Conference than Nebraska has right now.
Mason would have been able to implement his running attack with a bunch of 4 star running backs, a good offensive line, and 4 star receivers in place. Mason was also an old Woody player, and Earl Bruce assistant with the ability to recruit Ohio and they would have liked that. Lastly, the level of defensive talent at OSU was so high, that the failings here would not be an issue there on that side of the ball.
Mason would have had trouble not being a big success at OSU, although Tressel clearly was the right hire at that time.
Oddly enough, Mason (a good coach) and Gary Barnett ( a great coach) were both considered over the hill and damaged goods after getting fired from MN and Colorado, but both were a few years younger than Riley is now, and have not gotten a sniff at a good power five job, although probably many bottom feeder jobs were floated.
Maybe Nebraska should have just hired Gary Barnett.
Riley might do well at Nebraska, but this is a very odd hire. They probably should have just hired Scott Frost away from Oregon up front, or offered Gary Patterson 6M a year.