Your math doesn't make sence in real world. Either he run his 1070 at 100 or 150 wats PL, the hashrate for ETH will not increase, it will remain at 30-31 MH/s. So he is effectivly saving 50 watts per card while getting the same hashrate, what's wrong with that?
There is exactly 0 chance that you can cut the power consumption of any electronic component and receive the exact same output. If you could, Bitmain would already have an S11 on the shelves that uses 1 watt. If my math fails to make sense to you, it's likely because you don't even math, bro.No one ever said the SAME exact output, so of course you're going to make assumptions to fit your (greatly warped may I add) perception.
150W gives me 31 Mh/s whereas 100W gives me 30.5 Mh/s so in all practicality it is essentially MORE EFFICIENT (as we've been trying to tell you) to do it this way. The only reason why I questioned if a lower PL was "bad" was based on what you guys were saying and making it seem like lower wattage was a "bad" thing. But I can see now that I obviously can't take what you say with any type of validity, but I guess people will firmly stand in what they think is correct even when they don't have a clue what they're talking about. So before you go making smart ass statements like the one below:
There is no part of me that will ever understand the idea behind taking 10 cards and intentionally turning them into 7 
Maybe you should at least try put forth a worthwhile post that helps instead of trying to belittle someone in a topic you are obviously less versed in.
Also back to my original question:
By the way, a little off topic, but do you guys think it's ok to run 12 GPUs (all 1070s except for 2 which are 1060s) on two EVGA G3 850W PSUs? I downvolted all of the cards and each 1070 is right around 100W/piece and 1060s are roughly 80W. Been stable now for over a week, just wanted to get some feedback regarding this setup.
I friend has 1070/100W MC 1160 and 31.4 Mh/s on etc and as you said running stable (in this case for weeks).
As said before the 1060 can usually run stable a 75W but I prefer 80 ~ 90.
Your PSUs have enough Watts as surely you know. I guess that if well connect they should run ok.