I received this gun about a week ago and waited to test it out before writing a review. Overall, I am very pleased with the gun as a whole, and would recommend it to anyone who is looking for a high quality M4 style airsoft gun. When I first test shot the gun however, I ran into a reoccurring issue that some KWA's seem to have out of the box - the hop up. It seemed as if no matter how high I turned my hop up on the bb's would still nosedive after about 80-100 feet, so I knew something was up. I personally own other KWA's and am familiar with the standards of the brand, and that I should be getting 200+ feet out of this gun. I checked on KWA's forum on their website (which was very helpful), and sure enough, other KWA M4 owners were having the same issue. I was told by numerous people that the issue was that there is a film of grease on the bucking that causes it to make the hop up go wonky, but that the grease could easily be removed by soaking/washing the bucking in warm, soapy water. After I did this, to my surprise the gun began shooting flawlessly, straight as an arrow. Easy fix for a big problem.
Now for the externals, you can expect only the exceptional quality that KWA offers. the rail system is a Noveske NSR Keymod system, which looks and feels badass. Its based off of the real steel version, and makes it easy to move rails to where you need them, and have none where you don't, thus making the gun a lot lighter. The selector switch is nice and crisp, and everything is rock solid on the gun with the exception of the crane stock. It tends to have a slight bit of wobble, but I have yet to see a multiple position stock that has no wobble. The mag included is also very nice and feeds perfectly.
Now the gun is shooting a little less hot than other KWA M4's, around 330-340 FPS, but that shouldn't affect your effective range on this gun one bit. It still carries the bb's far, and with good groupings. The fire rate is also great, shooting about 19 or so RPS with a 9.6v, and obviously higher with a LiPo.
Overall, I love this gun and intend on investing a lot of cash into it.
Great rail design
High Quality mag included
Great hop up and bucking
Nice 2GX KWA gearbox
Gun bag included
Hop up had a slight problem in the beginning, but was easily fixed
Slight wobble in crane stock, but that's with all multiple position stocks
Slightly lower FPS, shouldn't affect range much
Nothing else to complain about!