As a previous poster said, Deluxes are 15% off during Value season, the Mods & Values are 20% off.
I just changed my AAA room only reservation at the AKL to the new public code, because it was cheaper than the AAA rate. I booked directly through Disney and had no problems making the change.
I think the public code for Mods is about $10 less per night than AAA, but it may be better to stick with AAA at the values. Someone else may have a better idea.