I don't even like what we have now, but that's largely due to the subjective nature of ESPN's selection committee.
That's why one thing I DO like about a potential 8-team playoff, would be IF the subjectivity were partially removed by forcing the use of the objective criterion of "P5 champs only, earn the autobids." Then of course ESPN could still worm in Notre Dame or backdoor a second undeserving SEC team using at-large, but at least for every team in the P5, you know before the season the one guaranteed way to get into the CFP.
And sure you might get a 9-4 type team as a conference champion, but that's actually a fault of the conference and how it selects its champion, not a fault of the playoff. If conferences played full roundrobins and no CCG, you'd reduce the chance of a total clunker team making the playoff.