KAC = Knight's Armament Company
But, to be fair, they are 2x+ the price of a 6920.
IMO, as good or better: YMMV
Stag, Sig, Spikes, S&W, Noveske, Daniel Defense, LMT, RRA, Wilson, White Oak, to name a few recognized brands.
Some can be had for same or lower $$$ as a Colt, some are substantially more.
Guess it just depends on what you want to do with it & how much you want to pay.
The Stag 3G is a great buy.
MM