Wanted to add that with a 9.6V battery, the rate of fire on this thing is crazy. For kicks tonight I took off the receiver cover and connected my C8's 9.6V, 2000 mAh battery. I did a quick dry-fire test, and rof was significantly higher than the 8.4V 1400 mAh battery that's in the gun. I'd highly recommend this option for anyone getting this gun. There's plenty of room in the gas tube for even a 10.8 or 12V stick, but not sure if that would be pushing it too much.
I'll be getting some 9.6V stick batteries for this thing shortly.