I purchased this gun but with the retractable stock (A5 RIS) from another retailer but I wanted to weigh in with a review over here. It came well packaged, and the documentation I received was helpful and understandable too. It is a great feeling gun, shoots hard and fast (with a 9.6v 1600mAh battery .20g BBs) and is quite accurate at about 50 feet, which is how far I've tested it thus far and the ROF was as expected, though for indoors it may even be a bit too hot. The blow back is kind light, nothing like a GBB rifle by any sense of the word, but I suppose it's not one of those things that can pose a problem in the future, so I guess it's alright. It does have some weight to it; 100 players would be split on whether that's a pro or a con.
Overall, the gun feels sturdy in my hands. It is well balanced even given the retractable stock. The only issue I found was that there was a bit of wobble on the outer barrel and the charging handle tube. Once the battery goes in the wobble is gone, but for the obvious reason, but I am concerned about it and would like to look further into it and tighten it up. Also, there was a bit of wobble in the magazine as well, but that is an easy fix. The battery was a bit of a challenge to install. I chose a 9.6v 1600mAh mini nunchuck battery for this gun. There is a system to it and once you learn it it takes about a minute to get it all set up. The take down was relatively easy and I can also see that future upgrades will be hassle free as well.
Overall, I like it a lot! I would have no hesitation in recommending it as a CQB weapon. However, at this price, I might think about the licensed version, and get all the H&K trades, but that's just my opinion. For the price, I'd say, "why not!?!"
Great weight and feel
Shoots hard, fast and accurate at about 50 ft. (w/9.6v 1600mAh and .20g)
Poor man's chrono tested at 370-400fps
Easy breakdown for maintenance and access to internals for upgrading
Full metal, it's got some weight
Decent blow back
Smooth action and rigid function on the stock (mine is a MK5A5 retractable stock)
Wobble on the outer barrel and charging handle tube
A bit of wobble on the magazine
A tight squeeze in the battery compartment (again, mine is a MK5A5 retractable stock)
A bit on the pricey side
Rating: [4 of 5 Stars!]