Just got one in last week to play with. Shipping was fast, problem free. Ordered on Sunday, here by Thursday. Sent US mail. Instructions are easy to follow. Very simple and elegant design. Went out in blizzard and shot 70 rds through it. It works quite well. 3-4 round bursts very easy to pull off and controllable. Had it on a bushmaster m4gery. I felt with a drop down forward grip, would have been easier to handle and operate. Will not work with a 22. Not enough recoil to do what it needs to do. Will the ATF eventually outlaw it? Who knows what logic the ATF is using or going to use. I am pretty sure there is no logic. But, if you want to play with a full auto-esque gun, without spending 13-20k on a real one, or joing the military, it is a pretty good option for an m16 like experience that at present time is legal.
My choice of weapons are not always based on utility. Alot of them are about uniqueness and fun toys. This is a fun toy. The guy who designed this is also working on an AK version. That should be another fun toy.
If the ATF does declare them machine guns, the rear pin holding the stock to the buffer tube could be pinned, or space behind buffer tube filled in, making it no longer functional. But another 300 stock to add to your collection.