I've owned a G&G and personally i found it as useful as a trapdoor on a life boat, quite frankly it was poor, a few guns later i gave in to the pressure and bought a PTW and it is something else the thing feels solid as anything it is constructed amazingly and to shoot it is just something else its like nothing i've ever owned, i would never have anything else.
The biggest gripe most people seem to have with them is the motors but to be honest ive had mine for 2 years and im still on the factory one and it performs excellently