I think it might be possible to patch around this by weighting people by their projected future cycle count. Otherwise, I fear that you may end up with a Repugnant Conclusion even without an adversary -- a very large number of happy emulated people running very slowly would outweigh a smaller number of equally happy people running at human-brain-speed. Of course, this still gives an advantage to the views of those who can afford more computing power, but it's a smaller advantage. And perhaps our CEV would be to at least somewhat equalize the available computing power per person.