This appears to be a touchy subject...maybe it's been covered before quite extensively. However, I have to speculate again, that any comparison of a QR in a horizontal drop out, with a nutted axle in a track end, is defintitely apples and oranges. The contact area between the frame and a QR/axle in a horizontal drop must provide substantial stability. The drivetrain force is directed partially into the top edge of the dropout thus relieving much of the pressure on the axle to shift. On the other hand, I cannot for the life of me, see how a skinny QR with it's minimal threaded contact area could come close to a hardened steel axle/nut/washer combo when EACH are used in a track end (drop out). Excuse my layperson terminolgy. I'm not an engineer but these things seem fairly straight forward.
As my mother always said, "I'm from Missouri". We grew up in Toronto. I was confused for many years. I may still be confused about this issue. And no, I am not throwing down the gauntlet. But if someone has any emperical data on the superiority of QR's they would like to share, I'd be happy to be convinced otherwise.
Warren Young
Toronto.