Just finished setting it up on Nginx.
amber:~ mojo$ curl -I 'http://overloaded.io/' | grep X-Page-Speed % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0 X-Page-Speed: 1.5.27.3-3005
Since I moved from Apache to Nginx, PageSpeed was disabled, or better, not even installed.
Should be writing something about PageSpeed and the install process soon!