Two rounds in, here's my thoughts on the 12-team playoff system...
What works:
Just about everybody that deserved a national championship shot got one. Boise State got a deserved chance, even though they lost the game. Big 12 and ACC got shots they wouldn't have with a 4-team playoff. Nobody goes home deservedly short changed (except maybe Oregon)
Home games in the first round. Electric environments, even in blowouts. Good enough that they should do it for every game until the championship.
This was the perfect year to expand, because a 4 team playoff would have been a disaster. Who would have been the 4 teams? Oregon, Georgia, Notre Dame, and then choose between Texas, PSU, OSU, Tennessee, Indiana, Boise State, Arizona State? Nobody would have been happy, and a team that will likely be in the national championship game wouldn't have had a shot.
What isn't working:
4 byes for 4 conference champs. All 4 lost, 3 of them handily. Whether it was the long layoff or the seeding being messed up based on there being only 2 deserving conference champs, nobody was rewarded for winning their conference championship game. I'd propose expanding to 16 and inviting every conference champ, so the lower-tier conference championships at least have meaning. Then everyone gets a home game that is ranked high, and everyone is on a level playing field for the quarters.
Quarters at neutral sites after first round at home sites. It was almost a disadvantage to be a conference champ this season, even with the byes.
Having all the games on a network in the SEC's pocket. All we heard for two weeks was how the SEC got shafted and nobody else deserves a spot at the table, only to watch every SEC team lose and/or struggle. Now they're left with Texas, a team not even in the SEC a season ago and a room full of analysts and Nick Saban left with nothing to say.