That would be an arbitrary and rather useless criterion.  Bitmain is relatively competitive in GH/W, which at this point isnt worrying anyone yet anyway, and they are competitive price wise. Who cares what process node they use?  If Bitmain is ignored its much more likely to do with their relatively low volume.

That said, Im also quite curious who is piling on the hashrate right now. I was expecting this difficulty period to be relatively flat, since none of the well known names are shipping, aside perhaps from Bitfury and ignoring overpriced 65nm kit from BFL.  Instead of flat we've added about 3 PH in 9 days. Thats is a big surprise to me. Is there any chance part of this is KnC private mining operation that they now may or may not sell off?