They are pretty well made, and most of the parts on them that could break seem to be ones that could be easily repaired. Mainly: The front hand guards are prone to cracking at the takedown tabs and should be reinforced - do it before they actually break. The bolt hold-open spring is pretty mickey mouse and I would be concerned about it coming off. But aside from that they are a pretty solid piece. Typically they don't get shot much because of their relative scarcity, but I have yet to see one that is "broken down". They sure are attention grabbers at the range.
And yes, as GT says, the long and the short of the story is that the manufacturer didn't intend them for public consumption, and we were lucky to get them.