Bought this gun a few months ago, and the day after delivery, I played a full 8 hours of straight airsoft with it. I was shocked at the performance out of the box. It felt very solid (surprising, since the receivers are plastic) Accuracy was pinpoint, the iron sights were impressive, and the magazine fed well. I'm not a personal fan of high caps, but this one was beastly (gun came with a wind key; a great plus) The battery provided is a 9.6 volt 1500 Mah nunchuck. It fits in the crane stock like a glove; no wobble that I could tell. One of the only downsides to the gun that I found was the flash hider, which has two screws holding it in. One of my screw heads came stripped. I'll find a way around it, but it's a little annoying.
Outstanding feel; very solid
Accurate as all get-out
Battery provided is very good (gives the gun a fantastic ROF)
Free float rail! (Makes this different from other M4's)
Magazine feeds surprisingly well
Flip-up iron sights are awesome
Flash hider is tough to get off
Crane stock wobbles just a bit
Overall, fantastic gun that looks and feels awesome. Don't let the cons dissuade you from buying this work of art from Echo 1.