A change I'd like to see: If you're conference champs in the SEC, ACC, Big 12 or B1G, you have an automatic spot in the 12, but NOT an automatic Top 4 seed and a bye. The Big 12 having an automatic top 4 spot is ridiculous. Same for the ACC, though to a lesser degree of ridiculousness.
Also, we have to find a way to address situations where a given team is in the Top 12 going into its CCG, but loses, and another team who didn't play in its CCG takes their spot in the playoff.
Honestly, I'd like to see the old BCS formula determine the Top 12 seeds and tee the tournament up from there.
The difference I'd have from the old BCS is transparency into the computer algorithms.
I understand the developers' desire to keep that proprietary. So the new role of the committee would be to bless the computer logic. Have them sign an NDA, evaluate the logic, and for algorithms that pass muster, include them in the computer part of the BCS.