I recently purchased this gun, and I must say that it's a wonderful piece of equipment. Hits very hard right out of the box. I had mine chrono'd at around 320fps, stock. Also, the rate of fire on this beast is impressive. The high-cap magazine that came with it is junk, however, so get some different magazines ASAP.
Full metal body
Full metal interior
Very fast rate of fire
Somewhat hard to upgrade externally, due to the short, spetznaz style barrel.
Plastic hand-grip, however one of the only parts of the gun that is plastic.
Battery is a little hard to get into the stock, without some minor routing work done.
Overall, a fantastic gun that I cannot recommend enough.