The thing I always loved that was unique about CFB was how much it required you to be consistently good, put together a full body of work, and maintain it from the get-go over a full season without a single bad week... not just get hot at the right time, or be a talented team who didn't always show up.
Expanded playoffs are going to kill most of that, but it would be great to see that undefeated accomplishment awarded one last time.