Any reason that Google Analytics SiteSpeed would consistently be 2 seconds higher than expected? We've tried using various website speed tests online (pingdom shows sub 3 seconds, etc) - along with testing on various actual devices/locations.
Our PageSpeed Insights scores are in the 97+ range, as are our scores on most other similar services (pingdom, etc). We're also using many things which should speed things up, such as mod_pagespeed, gzip, optimized images, AWS / Cloudfront, etc.
However, our SiteSpeed via Google Analytics is consistently in the 4-5 second range. Are there any factors that could affect Analytics exclusively, that would inflate the SiteSpeed ranges incorrectly? If not, are there any other suggestions on an approach we should take here to bring them down?