I have thought off and on of getting one, and yes, without der papers, pleeze, putting a gun in the stock is an illegal SBR, but main turn off was stock was cheap enough, but sights, sling, light etc (and mainly the sights) about doubled the price.

https://www.youtube.com/watch?v=BvAckAreyss

Looks like fun, but not $400-$500 with sights when I can buy a 14.5" just as legal Colt upper for $150 more....just mine own economics, but have been very tempted on the Micro, yes I have.

PS- considering how the ATF has ruled that possession of a torched in half STEN along with an appropriate sized piece of tubing constitutes possession of an illegal machinegun due to "obvious intent", it would be a wonder if same not true of the Micro Roni plus a Glock, but, you never know about those guys. They briefly ruled even a shoelace and a semi-auto .22 possessed simultaneously was a machinegun, as well, but rescinded that one.