That's kinds what I was thinking, so close to the center... so maybe it doesn't matter? I do not notice it on my mountain bike, but on those, disc brakes are mandatory with the crap we ride through. Mud, water, etc would surely weaken braking power.
Rotating mass will still affect braking, wheel directional changes and what not. Still sitting on the fence on this one since I'm not sure but the question still is unanswered in my mind. I can't help but think the cons outweigh the pros...