FWIW, my Fox Hawk flew as a 12S 6600mAh lipo 4kW EDF at 17.5lb (8.75kg) and flew and aerobatted very well. General handling was great. I was pleased to replace the EDF system with a Wren 44 Gold, saving about 4lb in landing weight and enabling much faster turnarounds without all that recharging of monster lipos. However, the plane did take off and land nicely enough at the heavier EDF weight.

Gordon