Another vote for AF1, it made a difference you can feel and added some nice growl under the hood. Havent seen any MPG increase, but then again I cant keep my foot out of it either.

 

Theres a mechanic at the ford dealership I work for has been telling me the AEM Brute Force intake and a SCT Flash Tuner (long as you got someone good to program it) would be the best thing for my truck and I got the same as you do