The charging handle on my Gen II Kriss was stiff but as Matt308 mentioned with some lubing and use, it is fine. My problem was that I kept pulling the charging handle too far because you tend to forget it's for a .45 case not a rifle cartridge. I have had the bolt fail to lock back on the last round. It happens about once every 50 rounds. This is with the mag that came with the gun and some other ones I have tried from a Glock 21 and a mag from JR carbine so it's not associated with one particular mag.
I had a couple of mags fall out during the first 200 rounds but during my last session that never happened once in 100 rounds. I am thinking different ammo made the difference here.
I did quite a bit of research on the Gen II and I think (hope) the issue of rounds going off when not in battery and the receivers cracking have been resolved. For a gun costing around $2000 there shouldn't be any major issues like that IMO. The trigger is a huge improvement over the last one. Certainly is a fun gun and accurate enough.