I don't even have the paperwork yet because I'm still in the decision stage of which I want, though the Tactical Innovations Tac-16 will likely be the one because I'll have the option of using it for .223 and also .22LR since I can take a steel brush and take care of the lead deposits the 22LR will leave on the baffles. Of the major brands, it's the only one that is user servicable (to a point).
I've been in contact with YHM, Advanced Armament, and Tactical Innovations and all 3 seem like reputable companies with good communication, but I like the features of the TI the best.
I'm hoping to have the paperwork started within the next 6 weeks or so and within the next 3 months have it on a barrel. You know how the NFA branch likes to drag their feet in signing the forms.