Mine is Olive with a locking trinity feedneck and a matching ul barrel.
Efficiency: not sure exact numbers but i played four games with it and never refilled.
Feel: I like the way the gun shoots but the frame is to fat in the grip imho. And the plastic trigger sucks and is stiff due to the sear/ pancake noid.
Play: First and foremost i love automag guns. This gun shoots alot like the automags very accurate not the fastest but it does ramp ( do you need more that 15 bps NO!!!!!). I really liked playing with it you need the right paint because i used white box and shot tits then used draxxus midnight and was all over the place.
I thing for the price this gun is an awesome first gun, or perfect for rec play. I dont think many spped ballers will like it.
Needed upgrades: Needs a locking feedneck, trigger, barrel and hopefully a Ul frame will be released.