Once you get to 8 teams, you produce a "playoff champion", nothing more than that. The odds are that the "best team" is not going to win such a playoff.
So this is interesting because we have a playoff champion now, but once it gets to eight teams, it feels different somehow. Like, lets look at SRS, which is a mildly blunter tool to decide best, but more nuanced than record.
Since they playoff started, we've seen two of the "best" team's win the playoff. This accounts for all games, so in theory, the playoff winner gets the biggest boost. (Biggest surprise for me there, 2015 Clemson being rated behind Bama because of how good that defense was. That Clemson team was better than the title team, I think).
BCS missed the top team in 2010, 2007, 2006, 2003 (kinda), 2002, 2000 and 1998.
Anyway, food for thought as we're stuck with NFL games till the Egg Bowl.