BenL
John Galt Speaking.
Remains to be seen what the real world accuracy is, and at least word on the street is the barrel was determined not to be rifled by the ATF, but they don't have a ruling on the completed firearm yet. Still can't go shorter than 11.5" or else it gets into AOW territory, so while better than 16", think the braced "pistol" will remain the best work around. The tech, and proof of how arcane and pointless the NFA is could be useful down the road though if we can muster a challenge to remove SBR/SBS from the NFA.
Especially since braces are getting more and more...functional (*COUGH...morelikestocks...COUGH*)
The SB Tactical pistol braces are about the most functional I've seen, so far.
Here's my 10" Noveske 300BLK build, also doesn't require a stamp and does substantially better than 4 MoA (with a scope and 125gr match supers, it's sub 1 MoA.)