Speaking of quality, I've run mine for quite a while offroad.
The zinc gearbox is... it's bad. The airsoft gun jams too easily, and the tracks like to sag. The tracks on one side are a lot looser than the other, and it feels a little odd. The parts like to fall off, like the machine gun ammo box and some of the anchors for the tow cables. The tracks are squeaky as hell too, so you'll know when the thing comes rumbling down the grass / road.
I still like it though - now all I have to do is to stop grass getting inside the tank, which is always a pain.