They've gone from 0.4w/GH to 0.67w/GH which significantly impacts both the running costs AND the length of time these will be viable to run.
There was never a 0.4w/GH for the full system. 0.5W/GH was what I used for my calculations and I am sure that downclocking will be possible just like with SP10.
6TH, 2500w is what it says, but using Guy's figure of 2700w that's still 0.45w/GH -> 0.67w/GH which is a 40% increase.
This affects the running costs, profitability and lifetime of the machine, and should also be considered when deciding compensation.