I like the 12 games because it makes it easier to insure six and maybe seven home games. It doesn't lengthen the season so much as it reduces the number of off weeks from two to one.
I like the four non-ACC games to be:
1. UGA
2. A real easy home game early in the year
3. An SEC team signed up for a home and home - The Cocks,
Gators, Auburn, Vandy, Ole Miss, Kentucky, UT, Bama,
LSU - all would be fun to play once at home and once
on the road every ten years or so.
4. Home and home with some intersectional teams that are
good road trips for fans and make sense - Navy, Army,
Tulane when the SEC opponent from the above group is
tough, perhaps Notre Dame, Syracuse, Michigan State,
or a Texas A&M when the SEC team from the group above
is a lighter challenge.
That would be a fun schedule year in and year out.