I agree completely with JCM. If you actually look at aggrons stats, it's a physical wall, and walls usually don't have the best speed. This guy is great at his job, and his job isn't to outspeed. Most fighting types can destroy this thing with their speed and your waiting a movespot putting aerial ace in there. Just switch out if there's a fighting type and put something useful in that move slot. So NO, aerial ace is a bad thing on aggron.