From what I have tried with mine, the gd600 has helped the flight times. Yes the batterys are sub "C: size. To get a ten cell pack I had to use 2 servos for the alierons. Mine feels pretty heavy when it is ready to fly. I have not weighted it so I do not know how heavy it really is. I also have the landing gear on it. I do not have grass to fly from so I need them. I am using 4 HS-81MG servos. Hitec Spectrum 6 Rx. I had to do some surgery to get the gear box to fit. If you run DD there will be no problems.

I do not know anything about the Astro so I can not tell you anyting.

Dru.