I really dig mine. It's a sleeker and lighter option to the fat Sig brace. As far as shouldering... Well, it is an ATF OPINION that firing it from the shoulder makes it an NFA item. There's no written law that states this, just an opinion and no one has or probably ever will be tossed in a cell for doing so... That said, it is a government agency that thinks they know more about these things than anyone else... I have mine as a cheek rest and a space filler to make the pistol not look odd with a bare buffer tube. I like it a lot though and the dimpled receiver extension and set screw makes it a rock solid set up. Just if you're going to shoulder it and ignore all of our opinions not to bc of ATF's opinion, then just don't say anything in my opinion... Sure is a lot of opinions going on... Vern out.