Definitely depends on when you are going. Most of the time, AAA is the better deal, but I found a better AP deal for our June trip, granted it was only $25 less than my AAA discount, I can find another way to use that $25 at WDW.
Most AAA agents will NOT look for a better deal for you. I have heard of only 1 that did for someone. The one I originally used was not great the first time I used her, but she was well versed by the second time I used her and now she has decided to be a SAHM and the girl I have been left with can't keep up with me. I have had to do all the work, except calling Disney.
Suzanne