I have a Sub2000 in .40 S&W. Sight height doesn't make it the most comfortable to shoot but using Glock magazines and being able to fold in half makes it a pretty easy carbine to tote around.

Another board that is focused on KT firearms is https://www.thektog.org/

George Kellgren is an interesting guy and has some very novel design ideas. His production facility in Florida seems to be producing firearms as fast as they can but for some of the firearms, demand is clearly out pacing supply.