Ive owned 3 of their guns, a KU-16, a PF-9 and because I refuse to learn my lesson a KSG... ill never own another. They are a super innovative company that seems to refuse to try and match their innovative designs with quality materials or construction. All 3 were super uncomfortable to shoot, a while they could be reliable with the right ammo they were very selective. The KU-16 would either run 95% or 20% based on the ammo, there was very little inbetween. And the KSG... gosh, what a horrible manual of arms (when compared to literally any other weapon in known history).
All that to say, they were all 3 kinda fun guns in their own right, but what I saw in built quality and quality of materials has sworn me off them for good. Which I'm kinda sad about since they seem to be one of the few genuinely innovative firearm companies out there. *even if they also have a few copies of other designs mixed in*