I worked on the Custom Conferences design with Ben Haumiller, mostly providing the details and mocks for the design documents. However, I have to say this is one of my favorites simply because it allows so much flexibility for each Dynasty. Given the fluctuating state of college football, we wanted to provide players with a way to customize it how they see fit. It opens up all sorts of flexibility for the player and increases the replay value of Dynasty significantly.
The UI is pretty slick and allows you to move teams between conferences and setup conference rules rather easily. Given the complicated scenarios that occur with college football, I think we accounted for most of them. I have played some of the most challenging Online Dynasties by leveraging this feature to move all 12 players into one conference.