The "G-36" Marauder kit on a 10/22 (at least with the stock length barrel) is non-restricted, even with the stock folded (no need to pin the stock).
As for how close it gets to the real thing? Well, I've handled both - the weight, balance, dimensions, etc. are all exactly the same as the real thing. The build quality of the result is, believe it or not, better than the real G-36. The real one can be a tiny bit loose feeling & a little rattly, whereas the Marauder (Nomad) is solid as a vault, with no looseness or rattles anywhere. Aside from a small difference in the appearance of the bolt, it is virtually impossible to tell the kit from the real thing. Of course, there is a vast difference in price, and you're actually allowed to own a Marauder...
Though I haven't tried it myself, I've read on other forums that some of the actual H&K furniture fits the kit - it's that faithful a reproduction.
To be honest, even after reading the great reviews on the Marauder kit, I was a little skeptical, but I really wanted a G-36 & couldn't have one. I specifically got it to replace my other "tactical" .22LR rifle, an AP-80, which was declared prohibited last year, seized, and destroyed, literally because it was too "scary-looking". In a fit of pique, and to assuage my desire to have a "tactical"-type non-restricted in my cabinet, I decided to get the Marauder kit for my old 10/22. In the end, even the great reviews didn't do it justice, and it puts a grin on my face every time I handle it or shoot it.
It's not as accurate as my bolt-action Savage, perhaps (although I've never bench-rested it to find out) but it's darned good. I put a RedDot on my Marauder, and my buddy & I have no problem consistently plinking golf balls at 50 yards with it. In my book for a tactical-style .22LR, that's as good as it gets. So far, in a brick or two of cheap, bulk ammo, I've yet to have a FTF, FTE etc. with it, using both the stock Marauder mags & a few old beater 25-rounders I had lying around.
Hope that helps....