It's not the addition of those magical "20 HP" that the XCAL is for. Its the way the vehicle drives after you re-program it. Torrie knows exactly where and when to add those extra ponies to make the vehicle seem like a totally different truck, and he can also control the transmission.
The dollars spent are well worth it. With my 87 octane towing program, I can do burnouts with a V6, chirp second gear and still get 19.5 mpg around town. With the 93 octane high power program, it will sit in one place and smoke the tires as long as I want it to. Try that on a stock Trac!