The latest CN fork - r, v4, whatever it's called - uses a little more power than the previous fork for my mix of RX 570 and RX 560 cards, but overall it is still using less than Ethash. And I am not even undervolting or power limiting the cards anymore (got tired of chasing stability problems - figured it was better to use 10% more power and not wake up to a rig that crashed right after I went to sleep [because that's when they always crash, amirite?]).