I don't like the stock motor (but that is for most brands), I don't like the self shimming gears as they don't work, their tappet plate is still weak and breaks easily, the piston is better but still also a weak point, the rest is okey, but even on these pretty expensive guns they still dont have a QC shell. Stock hop up is pretty good though and if I remember correctly their version 2 models of the hk416 come with a maple leaf bucking and nub out of the box.