The GoogleBot's aware of your cruft-filled javascript and stylesheet...

The Google toolbar

who uses google toolbar besides old IE users that need popup blockers? Seems like super high variance data depending on the end users connection, perhaps they get info from chrome usage statistics?

Dunno, but according to this article that's what they're doing: http://searchengineland.com/google-now-counts-site-speed-as-...

If every site is being judged by the same pool of toolbar users then it's fair, right? It's only the relative speed that matter.