A buddy has the 9mm Sub2000. We came to the conclusion it's a total POS.
Stock length far too short - and he's a very short guy!
Plastic sights that break when trying to adjust them!
The High-capacity Glock magazines are a real bear to load to full capacity.
Installing any optics negates the horrid little abomination's only redeeming feature - the ability to fold.
The cocking knob is in a very bad place.
On the other hand, it is reliable, and shot any ammo we put through it.
As a "pack & forget" truckgun, it may serve. Otherwise - "Friends don't let friends own Kel-Tecs!"
My buddy got the .40 Hi-Point Carbine and loves it! He shoots it far more often.
I have NEVER met a Kel-Tec - pistol or long gun - that I would trust my life to.
This is my own opinion, from direct experience - YMMV!