I understand what you're saying where different winds of brushed inrunner motors are concerned and I aggree with you completely.
Outrunner motors are different creatures with more magnets floating around. In the Delta, when the 4 magnets are being attracted to their energized poles, the other 10 magnets are just waiting their turn to do their work.
What makes me wonder, 8 magnets versus 4? My theory is, the 8 will win the tug of war.
If I'm wrong, then I just am. But if I'm right, why aren't they building them this way? For one thing, heat buildup. Wouldn't the heat be 1.73 times greater also? I'm willing to try this, since the motor in the Revo has ran so cool.
But yes, even if it's just the better low speed commutation of the motor. That would definately be a benefit worth pursuing.