You have a point about a Diablo tune providing more flexibility and tuning options....however it also leaves evidence on the ECU that the factory programming had been tampered with....even when the stick tube is loaded back in...whereas the AFM does not and is a simple plug in (on - disables AFM) or pull it out (off)....do for those looking for all the benefits of turning off the AFM without the hassles of loading/reprogramming and risking voiding the factory warranty...it's a decent investment.