Mine has the latest flash and its fine, if anything it goes harder. My best friend owns a sedan manual, and side by side with my ute carying its hefty kerb weight I can still out accelarate him in any gear, slowly but noticably.
The difference in performance is greatly affected by production tollerances, my ute may have a lucky combination of parts, my mates may not have. Regardles of the tune, some will go much harder than others.
And if its that much of a hassle, fork out the $1295 and get an edit, then Ford can't touch your ECU any more and you'll be making 20% more power and torque, and saving fuel at the same time. Pays for itself