I'm running mine with a OS91 Surpass II in there and a 14x4W. It handles the weight no problem at all. I did have a magnum .70 in it and it could fly but it couldn't *do* anything
Fuel usage is extremely good I find I can easily get 12 minutes on 2/3 of the supplied tank.
It balances just fine with a 6 volt batt in the fuze, just behind the tank.