This is an interesting situation.
In football, the KSU vs MU game in Columbia drew over 10,000 more then the ku vs MU game in Columbia. In fact, I believe since they reconfigured the stadium to hold about 64,500 seats, KSU is twice in their top 5 crowds.
In basketball, it's really hard to say, but they sure do get upset when they lose to KSU, which has been early and often lately.