I imported a Spike's Tactical AR-15 (flat top) a little while back and I love it. It's a model ST-22, (marked .22LR lower) with a 16" barrel inset 1.5" with a slip-on fake can, light weight rail and a CTR stock. I also had them add a Timney skeletonized 3 Lb. trigger. I have since added a Eotech 512 and an Aimpoint 3XMAG magnifier.
I have to say that the fit & finish and overall quality is nothing short of awesome. Shooting .22 LR's makes it sound like I'm putting .223's through it with a fully functional suppressor. Really nice piece of hardware and really great people to deal with, I will no doubt be making more purchases from Spike's soon.
Getting DoHS to approve it for export was a whole other matter, and I wouldn't recommended it to anyone to go about it on their own. It's really not as straight forward as one would expect, just pay to have it exported/imported by someone like Mark over at Questar, (believe me, it’s worth whatever the cost).
I have also had the Canadian Firearms Center / RCMP assign FRT numbers for all or most of Spike's offerings, so that part of it should be smooth sailing from now on.
I'll try to get around to posting some pictures of it, like I said it's a very fine piece of hardware and sounds like a suppressed .223. It's great for getting everyone at the range to freak out and voice their opinion on what is legal or not. It's a fun way to meet new people.