In 2014, the Duke-UVA ACC Championship on Sunday on ESPN got a 2.2 rating.
In 2014, the Big 12 Championship (Iowa St.-Baylor) on Saturday night on ESPN drew a 1.1 rating.
However, if we look more historically at that coveted 9 PM Saturday slot for conference tournaments on ESPN, the old Big East held that spot for years.
In 2013, the Big East Championship between Syracuse and Louisville drew a 2.1
In comparison in 2013, the ACC (Carolina-Miami) drew a 1.4.
I think, given the success of Big East basketball in that Saturday night time slot and the fact that the ACC is perceived as the nation's best basketball conference (along with the Cardinals joining this year), the ACC will have better ratings in that night time slot than Sunday afternoon.
Sources:
http://www.sportsmed...-and-nit/#chart
http://www.sportsmed...13-14-season/3/