I have, and it's crack. In situations I might prefer it to gratons. I summed up my stance on it this way to a buddy. Sometimes you go buy some gratons, and 1/3 to 1/2 of the bag is mediocre pieces. When you buy quacklins (that's what Kirk's calls it), there isn't one bad piece in the whole box.
I've tried some copycat versions at other places, but none have tasted as good at Kirk's. I feel like every piece has a chunk of chicken attached to it, other places I've tried - it's just the skin.
Disclaimer: I am not a paid shill for Kirk's U Need a Butcher, but I am willing to be.