i would say that it is very near to being underpowered. i slimmed this plane down to 12 pounds 3 ounces with 5 ounces of lead in the nose. if i put the elevator servos up front i could lose that 5 ounces. i was even thinking about just one 8611a for the elevator on a pull pull. that could save a bit there. this plane is very stable in harrier and inverted harrier. knife edge is awesome. the only issue i have is hovering. it is a handful to hover. it always wants to pitch this or that was and the biggest problem is the torque effect of the engine. torque rolls are great, but to stop it from torqueing, you pretty much have to pull out and then let it back down. that is annoying and i think they should have put full span ailerons on this thing. they moved the horo. stab... why not make the ailerons bigger? they must have noticed in testing that the plane is impossible to stop from torqueing.