I got my new beautiful baby girl yesterday and she's pretty sweet. It's a G36C which was built into a K using real steel HK factory parts. The foregrip and stock are the correct K lengths, and the carry handle assembly was just ordered and will be here in about a week. It came with 6 standard mags and "the workmanship thereof is exceeding fine." The mags are solid and function perfectly, and the effect of the fake ammo inside is very well done. I know this is essentially no different from a "C" version, but few reviews have been done here on them beyond "I like mine." The gun itself is stock except for a TN inner barrel, so distance and FPS are standard, but the consistency is excellent and the ROF is very admirable. The batteries (2) are custom 9.6 jobs and put out plenty of juice. The most surprising aspect of this gun is how quiet it is. I haven't fired a stock C, so you C owners might add your thoughts here, but this is the most quiet AEG I have ever fired by a long shot. On semi auto I can seriously expect to take potshots at players without them being able to vector in on my position. On full auto, it's audible, of course, but still much quieter.
The C itself was already a solid gun, perhaps Marui's best "plastic" gun to date, but I was a little nervous about the feel and fit of the real steel add-ons. Mods were needed to make them fit properly, but the mods were well done and the fit is tight. The overall effect of this gun will be hard for Marui to improve upon when they finally release their own K version. I paid for this one out of impatience but also to get the greater quality of the real parts. I know a thing or two about injection molding, and the real HK factory parts are much more durable than anything else in airsoft. I am also an HK fan of many years and this is as close as I'll ever get to owning my favorite assault rifle, so the more "real" I can make it, the better!
In the end, I'm very happy with the purchase. It is what I was hoping for and more. I'll save my customary paintjob for the future Marui version and leave these real parts black, but that's about all I'd wish to do to this thing. I love it.