I preordered this straight away when it came on wgc and have had it for a while now. I suggest you remove the blowback operation rod because it grinds on the cylinder and gearbox case and fills the receiver with metal shavings.
Also ive never been overly impressed with vfc internals (owned a Scar H before) the gears and motor seem to have very little torque, they have trouble pulling back a systema M120S spring with 11,1v 15c lipo.
And the piston feels very brittle, the Scar heavys piston broke with M120 spring after few thousand rounds. Furthermore seems the AK is having some compression/l