I too purchased the FP tune, I have a 23 and wasn't interested in the Whipple kit. Personally I didn't think 98% of the transmission shifts were bad before the tune but its a noticeable upgrade, I really like it. For me the power seems to come on much quicker with less pedal input. The installation was extremely easy and its reversible. A couple of things to note:
1) If you live in a tight community and had "Quiet Start" enabled, it reverts back to off after the tune...sorry about this morning neighbors!
2) EDITED** My radio seems to stay on after I shut the truck off and open the door, only for a few seconds, but its definitely a glitch. After I close the door I can hear the radio eventually shut off. It didn't do that before, ever.