My flying buddy just got one. Same issues - it barely flew. Here is what he did (big improvement). I junked the speed controller and gearbox that came with it. He just used a 20amp Jeti contoller and an MJ 2.33 BB reduction GB. He uses 8cell 600ae packs. It flies much better.

I think if I had done it I would have also got the 7.2v s400 motor and used 10 cells.

It is a calm wind plane without ailerons and is not super responsive. They sure look great however.

Mike