We don't have the numbers in yet to be able to say for sure. But partly Bitfury is doing a full custom ASIC and will likely result in a more efficient chip overall than KNC's, at least for this generation.
If Bitfury are getting so many dies per wafer, why are they charging so much for it? They are basically charging similar to BFL to the prices I have seen, yet they are getting twice as many GH/s per wafer. So far KNCminer seem to be the only ones trying to get the ASIC price a bit more reasonable.