Lets see.... two Ruger Bearcats, one had a transfer bar issue. Walther PPQ-45, a trigger reset issue. Ruger American .45, slide stop issue. Charter Arms Pitbull, had the hammer over run the trigger (like two single action positions). Charter Arms Boomer, timing issue. RRI revolver, pin loose in frame. Serbu Super Shorty, misaligned barrel. Kahr PM45, chewed up front rail.
Non issues.... Colt LE6920, two "parts" AR's, CIA AK, KSG, Ruger Vaquero, RRI compact .45, Smith Governor, Taurus Judge, Smith J frame 357, two Kahr PM9's and another PM45.
And to be honest, I don't count a little burr removal, or an easy chamber polish "an issue". You can see, better and lower quality firearms... last three years worth for me, a mix of issues, some serious. Every one of those issues were corrected by the manufacturer, rapidly, or at least fairly promptly (from a few days, to three weeks). I had no "2nd trips" back to the mother ship, because I was able to explain the issue(s) adequately, and briefly in my "complaint" letter.
The KSG has one real issue, as far as I can see, and its that the chambers are phosphated (Parkerized). A very rough finish is left behind. Getting that to a smooth glossy finish will pretty much eliminate, or highly mitigate all the other issues we see, such as - bent operating rods, broken stock pieces, etc etc. But, a few issues are bound to creep in, so allow KT to fix 'em if they do.
My KSG did get a chamber polish, but it was working before I did that, with an occasional stiff extraction. Once the chamber was smooth as the inside of yer girlfriend's thigh, it extracts "like buttah". Some KSG's are a bit rougher than others I guess.