I think his system is just too rigid to compete well in the Big 12.
In his 2 good years at Air Force, both teams averaged less than 59 possessions a game, his best year was slightly over 56. I think it was more reasonable to play that pace with really disciplined players and in the Moutain West. In the Big 12, the better teams will overcome that. And he was able to get those teams to play decent defense.
One of his his real issues at CU has been defense. This year he has a pretty good offense, but a bad defensive team that seemingly doesn't even try to rebound. Last year he couldn't even get that decent offense from his SLTH system and the team was terrible. His first year was decent defense with average offense.
This year he's got his best team, and probably the 4th best team in the North, but the gap is big. Passing up NU and ISU is one thing, but making a substancial move will be too difficult if he keeps insisting on playing at such a conservative pace and with an offensive style that pretty much concedes 1 shot trips most of the time. There is just too little margin for error playing like that. I do think he's moving in the right direction with pace as this team is playing at nearly 68 per game, but as he continues to get some decent athletes I think he needs to concede a few runouts and send 2 to 3 people at the offensive glass if he wants to take another step forward and move past more than just ISU and NU in the league.