I think the committee factors in multiple criteria, but at the end of the day they pick who they believe are the best 4 teams in the country. I agree that the B1G winner SHOULD go, along with the SEC and PAC12 winners as those teams have gone through a gauntlet of inter-conference play AND won a championship outright. The Big 12 needs a championship game to legitimize their champion.
If you want to compare quality wins:
-Michigan has the best argument with 4 wins vs. Top 25 teams with 3 of those against now Top 10 teams. They have the best claim of 2 loss teams IMO.
-Clemson has the next best argument having 4 wins against Top 25 teams with 1 of them being a Top 15 team. Beating VTech would give them 5 Top 25 wins, that's pretty solid.
-Penn St. has 2 wins vs. Top 25 teams with 1 of those wins against a Top 10 team. Giving them another win against a Top 10 team, Wisconsin, AND being the B1G champ would make it hard to leave them out.
-Wisconsin has a good argument with 3 wins vs. Top 25 teams, keep in mind though that those wins are against teams ranked 21, 22, 23...not exactly signature wins. A win over Penn St. would be that signature win they need on a resume.
-Oklahoma has 1 win vs. a Top 15 team, West Virginia, which is moderately good, but not incredible. Beating OK St. would give them another Top 15 win, that's not bad but I'm not sure it's enough to leapfrog the B1G or Pac 12 champ.
-Washington has 1 win vs. Top 25 team, Stanford, who I wouldn't call a signature win either this year. Keep in mind that they have wins over a couple of teams on the periphery of the top 25 like Utah and Washington St. Those wins are as impressive as wins over Iowa and Nebraska, which is to say they a little bit impressive. Colorado would be a signature win.
-Colorado has 1 win vs. Top 25 team, Stanford. Same boat as Washington.
Pac 12 champ Washington vs. B1G champ Wisconsin would be a tough choice. Two teams with an equally mediocre amount of quality wins whose only losses are to now Top 10 teams. Ultimately I think record makes the difference, giving Washington the edge, but I can see arguments either way.