I'll keep this short, as my experience is fleeting, and doesn't require more than a paragraph or two. I had the opportunity to dink around with the Kriss Vector for the first time at a local gun show this weekend, and I have to say, I'm glad I didn't go in on one. The Vector has about 7000% more second kind of cool than most regular firearms, and to be honest, I still want on, but there were a few things, when taken in concert, that would make me hesitant to use it for anything other than as a range toy.
First off, the charging handle isn't a solid piece. Not a huge concern, but it feels flimsy in the hand when being racked to the rear. I'm sure it's plenty strong, but I felt like I'd rip it off if I got too aggressive. The fact that it flips back means that you're pulling on a rather long lever from the end as it tries to stay straight and pull a stiff bolt to the rear. If it was just a handle like the one you'd find on an AK, I think it would be better.
Second, my support hand rested on the bolt release and magazine release which, in my mind, means that the bolt is going to go home when the magazine is empty, necessitating a condition four reload (ie, no round in chamber, bolt forward) and the very recessed mag release may be missed when you need that mag out NOW. Not a big deal with the bolt release in most systems like the AR or AK series, but in this weapon, with it's stiff bolt and seemingly flimsy charging handle, I can see this being an issue in a tense situation. Some might argue that would mean going to a sidearm, but I feel these are critical design flaws in the system itself that for me, precludes it from anything other than a nifty range toy.
Weapons need to be intuitive and Grunt proof. That means that the controls need to be located in places that are easy to get to, yet protected from incidental contact- the Kriss doesn't have this. The mag release is set up to be hard to hit, and the bolt release is set up so that you can't help but make inadvertent contact if you c-clamp as I have started to do. I think the gun is tough enough to take a beating, but it needs to be able to be used without inadvertently sending the bolt home when you want it back, and the mag needs to be capable of being released by the support hand.
In closing, I would like to reiterate that I haven't put rounds through a Vector, and I still think it's an awesome looking gun, but there are BIG flaws in it that will, so long as they exist, preclude it from being a truly front line firearm. When you are going to drop $1300 into a single gun, especially one that fires pistol rounds, you want it to be simple, effective, and reliable. Where a pistol caliber short barreled weapon like a Kriss Vector would be used, there isn't time to press the mag release twice, or fight with a tough bolt. And who the hell puts the tapped holes for the rails into a system, but doesn't include the rails with the weapon? For $1300, I'd expect a better system and at least ONE rail section for the side. Until those issues are fixed, I'll just put my hard earned money into simpler, cheaper systems that work.