I'm rather surprised that no one has written a review on this wonderful gun, so here's my go at it.
This gun is amazingly realistic. Functioning charging handle, functioning bolt catch, functioning forward assist, AWESOME RECOIL, and it can be easily field stripped. I believe this gun shoots around 340 fps on .25's, so this thing shoots HARD. Note that, as with any gas gun, the FPS will drop the more you fire it. On top of that, this gun is super gas efficient, and you can probably get over one mag emptied with a charge of gas. Also, it works better than most GBB M4's in colder temperatures. The only problem I have with this gun is the weight and price of the magazines. Because these magazines hold only 40 rounds, you're probably gonna want to carry around a lot, and those things can slow you down quite a bit. However, the power and the realism of the KWA LM4 GBB makes it a great field weapon.
Easy Field Stripping (Maybe a bit difficult for a newbie)
Shoots Hard (Might be a little to hot, but IDK, someone take out the calculator)
Good/Decent in cold temperatures
Rating: [5 of 5 Stars!]