Phil,
I just installed a few switching PDUs at my data center and here are numbers from the wall that I have on some of my S9i-14.0 miners. All are running 20181107 firmware. I may install some other firmware on the miners when I have time to monitor them. Temps are around 62-67. Firmware has been rock solid and I did not have to install the upgrade failure firmware first. I believe I have a total of 55 S9i-14.0 miners running this firmware so this is just a sampling from 1 cabinet.
Average Real Time Real Time Power W/tH
14.010 13.955 1207 W 86.5
14.126 14.124 1210 W 85.7
14.226 14.279 1195 W 83.7
13.988 13.985 1190 W 85.1
13.996 13.927 1162 W 83.4
These are the best numbers I have ever seen if indeed these are the numbers at the wall. I have metered 240v, but only in amps. I can therefore only calculate approximate wattage but not near exact. I just got a bunch of 13.5 and 14TH S9s in. I was really thinking that the 3rd party software with the new ASIC boost enabled was going to be my best option, but this 20181107 firmware result is the best I have ever seen posted I think by at least 5%.