I would not ruleout S7's at all.At this point I figure bitmain has got the lowest price they will on producing them. I also figure they have very good electricity prices at internal mines. So add those together they still can profit off S7's I think.
I think S7 is at least a portion....how much we will likely never know.
I would almost be willing to bet the S7's were a
large portion of that network hash rate increase. I honestly believe they were not able to sell all of the batch 8's. I don't believe they sold very many batch 9's and batch 10's at all. They simply posted them as being sold out and incorporated them inside their own mines. I would think they are willing to do the same with the batch 11.
Yes, BitFury may have increased "some" of the network hash rate but I don't believe they are the main culprit of the significant increase we've had lately. I believe it's mostly Avalon 6's and Bitmain S7's that came on line in China. My speculation of course.
EDIT: If all of it were S7's and Avalon 6's, it would be a total of approximately 30,000 rigs manufactured between the two of the for the increase in hash we had over the past 2 weeks. Does anyone think that is possible?