If you can fly/hover an Axe, flying a T-rex of any size is a piece of cake. I too moved up to a T-Rex and belive me when I say that the T-Rex is MUCH easier to fly/hover!! The bigger the heli the more stable it is. Its plain physics that make the larger helis more stable. As for building the T-Rex, you could save yourself the headache and get a T-Rex450SA (comes preassembled). I got the 450SA but took the whole thing apart because I wanted to see how it all went together.