Talking full sacle, The Edge originally had a flat tail section. It was updated to airfoil. Thye really big difference between an Edge and an Extra is that the Edge has no taper on the leading edge of the wing. All Extra's do.

Now history of the Extra. Originally there was the Extra 230. It had a mid wing and flat tail section. The 230 was designed to compete with the Laser. The 260 was next and is best known for taking Patty Wagstaff to 3 world championships. It was a little cleaner then the 230, airfoil tail section, mid wing , some composite construction and had more power. Walter Extra assigned the numbers 230, 260, 300 for the HP ratings of the engines used. The 300 mid wing was next. Two place mid wing with 300 HP, that was followed by the 300L low wing 2 place, still 300 HP and the 300S Low wing single place. The latest I think is a 300 SX which is a cleaned up version for the Red Bull races. The current HP available I think is 330. The funny thing is that to the best of my knowledge there is not a full scale Extra 330 regestered. Someone ordered a 300S with larger elevators and rudder. the owner of that aircraft designated it as a 330 but in fact regestered it as a 300.


For R/C, I think the Extra flys a bit smoother and lends it'self to IMAC type flying better then the Edge. The Edge does not want to do snap rolls and spin entries as well as an Extra. The wing planform is just to stable to get good clean stalls out of. Both will 3D but that is more of a matter of setup then actual design