v8 -> v9 power consumption jump 
~35%
~35%How did you measure it?
What cards do you use?
I see much less jump, may be 5-10%.
Cause we may be close to the edge, when even xpm gpu mining becomes unprofitable in terms of electricity bills...
v9 powertunes +20%, thats more or less like scrypt for me. i lowered it to -10% and had to lower the clocks a bit, the results are a bit slower but its a must for power savings.