KD does have a dynograph, comparing against OVTune and stock. Their claims of higher power numbers are not wrong, and I believe they claim an additional 20-30+, but the power is up high in the power band, above 5k rpm. Where the truck doesn't need it. In addition, it removed the additional power gained down low from OVTune and reallocates it up there. Down low is where the truck needs it.
This means that the "power" that people feel down low is simulated, relying heavily upon throttle modifications in order to have the driver blast through all the less refined parts of the tune, to give the impression of power. Is it effective? I suppose so. Lots of people claim to love the tune, although lots of people are also not privy to the details of how various edits are commonly made to the 3GT tunes, or even care. Is it an ideal tune/method? Idk. In my opinion, no, but that is my opinion. All I can really go off of from there is that OVTune/Mat (the only actual/professional tuner in this whole mess) had stated that there may be only 10 more horsepower remaining available to draw out of these N/A 3.5L trucks and seemed to imply that it could come at the cost of longevity. Maybe he was right, maybe he was wrong. Nobody has been tuned long enough or with enough miles yet to really say for sure.
TLDR; KD has a dynograph, with numbers. However, people should know how to read a dynograph, which isn't difficult to do.
To answer the other question about which user-edited tune has the least knock, that's probably Coyoza, but I am biased. Very smooth. Coyoza tune is for the 6MT only however. A MT tune made by a MT owner on a MT truck, for the MT crowd. Not an AT tune converted for MT trucks.
Idk about for the AT's.