And there's no way a 13 seed VCU could make the final 4, right?
I think pretty much every game would be fairly competitive. I'm sure there would be a couple blowouts here and there, but who knows where they'd be (see: Louisville / Florida). I'd expect 10+ good games out of 15 in the above bracket.
The reason I'm strongly in favor of 16 is because it allows for an auto-bid for each conference. Would dramatically increase the national relevancy of each conference title game, which would benefit college football as a whole, imo. Think about how much more exciting the Sun Belt title game would be if it was for a spot in a playoff instead of a spot in the Godaddy.com bowl. In this way, every school in the FBS has a shot to win the title. That's how sports should work. If you don't feel that the Sun Belt winner deserves a shot at a championship, then you should advocate for the biggest ___ conferences to split away from the Sun Belt type conferences.
The main argument against a 16 team playoff seems to be about protecting the importance of the regular season, which is pretty funny to me. Ex. "Alabama-Georgia was a national semifinal game!1!!!!1!1 A playoff would destroy that, since both teams would make the playoff". First of all, that SECCG would still be incredibly important for seeding (pretty huge gap between NIU and Arkansas St, for example). I promise, Bama and UGA would still have taken the SECCG extremely seriously. Additionally, a 16 team playoff would guarantee two national semifinal games. Nothing is lost. The semifinal(s) would just happen later in the year, and we would be nearly guaranteed two good ones (instead of a de facto title game play-in between Notre Dame and a Wittek-led, playing-for-pride USC team).