I have not run a Fred tune but do run a Doug tune. After studying the graphs that were posted, I can see that Fred's basically adds some power (torque and hp) on the low end. Unless I am missing something, there does not seem to be much difference in the mid-range and upper end. I don't have dyno numbers on Doug's tune but I did do some performance testing before and after and I can tell you there is a definite improvement in performance in the mid and upper range with Doug's tune. I didn't test low end.
I timed 40-70 mph and 50-80 mph full throttle acceleration in 3rd gear with a very accurate stop watch. I did it that way to eliminate variables like wheel spin and shifting gears. The different speeds were to represent mid-range and high end performance. The 87 octane Doug Performance tune was quicker by 0.7 second at 40-70 and 0.45 second at 50-80 compared to stock. The 91 octane Doug Torque tune was quicker by 0.7 second at 40-70 and 1.2 second at 50-80 compared to stock. I ran these 2 to 3 times at the same location to get a valid average.
I also tested the 91 octane Performance tune but it did not give as much improvement in performance as the 91 octane Torque tune but did have the best gas mileage improvement. I think the 91 octane Performance tune needs to go all the way to red-line to get the most out of it. I discussed this with Doug and he agreed. I decided not to run any higher speed tests to verify my speculation because I was already pushing my luck at the speeds I was running.
2002 FX4 Bright Red Supercab 4.0 SOHC, manual 5-spd & Tcase, 33" BFG MTs, K&N air filter, Modified air box inlet, Gibson SS cat. back exhaust, Bama flash, Hidden Hitch round receiver, Rear helper air springs, Electric trailer brake controller, Line-X bed liner, WAAG bar with KC lights and Wildernest shell.