Yes i like good power supplys too but when it came to making a mining rig i made a lot of math and i could't justify a higher price with 2% lower electricity[the difference between lets say bronze and silver PSU,and the difference between a PSU at 95% load and 60% load is even smaller ~1-2% when we talk about nice PSUs].And then also i think the commonly cited usages of the cards are exaggerated but i have not made any measures.