For Harriers, Elevators and hovering the straight leading edge of the Edge seems to be best. For tumbles and spins the swept wing of the Extra, SU and Cap seem to be better.The placement of the h stab on the Cap seems to give better performance for rudder in pos and neg maneuvers. A longer fuse seems to aid in stability and torques but it hampers the tumbles...

As you stated... There is always a trade off. I would be curious to see a raised stab placement on a straight edged wing, mixing the Cap and Edge a bit. Light loading the wings, slightly longer tail, more cord stretch than lengthening span. O'... Obscene power too.

Just thoughts...

Bean