Ah... so not one individual personality, but a "city" of of AI's? Well, if I see it not as a "robotic superhuman" but "robotic super-humankind" then it certainly becomes possible - a whole species of more efficient beings could of course outcompete a lower species but I was under the impression running many beings each advanced enough to be sentient (OK Yudkowsky claims intelligence is possible without sentience but how would a non-sentient being conceptualize?) would be prohibitively expensive in hardware. I mean imagine simulating all of us or at least a human city...