"Hemmorage of airspeed" = induced drag. There is no difference between hard turns and slow flight only airspeed. High AOA that is required to fly a delta (tailless) slowly requires lots of power. "Glide" at lower airspeeds for deltas is very steep. Wake turbulence that the pusher has to "chop" through is the reason for lower efficency. Also the other downside of pushers is that they usually have to spin a lower A/R propeller (diameter) due to interference issues with airframe structures and the ground at rotation. Loss of efficency. The beauty of electric is when you want a sample period, turn the motor off. If it is a sailplane type platform you have, glides can be well over 50:1. @Iron, Tell that to the guys that fly their sailplanes over 400mph....oh, nevermind they do blow them up. We are flying our "powered sailplanes" over 150, even 200mph without the issues you describe. Visit the "High Performance" forums on RCGroups. My deltas I designed 20 years ago, needed 2KW (glow) to get in the neighborhood of 180 and the "sailplanes" of about the same size only need 1KW to break 200. Yeah, build them out of wood, they explode. Composite is the only way to go.

Brooks