Is it really?
KU is down from last year.
OSU is probably about the same.
Baylor appears to be a little better.
ISU is about the same.
KSU is down.
No real changes in WVU, TT, and TCU.
Texas is better, though I'm not sure how much.
OU is probably about the same.
Looks pretty comparable, at this point, IMO.
Team 2013 Kenpom 2014 Kenpom
Kansas 8 8
OSU 22 3
Baylor 29 37
ISU 27 22
KSU 21 86
WVU 125 60
TT 233 121
TCU 264 201
Texas 89 55
OU 49 65
So the Big 12 is better according to Kenpom, but not by a lot, and mostly just at the very bottom, which doesn't help out a bubble team much. Wins over bad teams are valued much higher than wins over terrible teams, and there' a little harder to come by.
However, where the Big 12 has excelled is in the renkings like Sagarin ELO Chess and RPI, which don't try to be predictive and don't use margin of victory. To my knowledge the comittee looks at wins and losses, but not really much at margin. And the Big 12 is killing it in RPI, where it's further ahead of the next best conference (Big 10) than the Big 10 is ahead of the 4th best conference.