Honestly this doesn't seams correct.
1070 average is 450 Sol/s; Getting: 430-500
1080 Ti average is 750; Getting 710-800
Already tested with few cards without any additional clocking. Of course, it can go up but this is as default setting.
I have many different 1070's and I agree with your statement. Most ppl will be able to get ~470-480 @ 120-130W