Midsole positioning improves time trialing and climbing for roadies. For triathletes it seems a no-brainer as it reduces the work of the calf muscles, which do little more than stabilize the ankle, as the bigger muscles of the thighs actually produce the torque. Since the calf is minimally worked with the midsole position, the triathlete starts the run with much fresher calf muscles, the primary movement muscles for running. Seems like a pretty good thing to me.
By JoeFreil