I'm happy to write a review of an awesome plugin, and this is one of them.
Testing revealed that jQuery was the single largest download on my pages, weighing in at 31.7 KB.
Not surprisingly, it was also the slowest aspect of the site, taking about 865 ms to download, or worse.
My nature as a speed freak, i look for ways to speed up a site. Images have been resized to their display dimensions and optimized. The largest image on the front-page is 12.3 KB, which is a lot less than jQuery.
Minify removed very little or no download time, perhaps because the library was already cleansed of whitespace.
Amazon Cloudfront CDN speeded up the download to 619 ms or better.
The site is on a AWS Ubuntu server so it was possible for me to exercise complete control over the apache2 httpd setup. mod_pagespeed was added after a lot of tinkering. That worked very well on the site as a whole, but did little to the large jQuery script. Nevertheless, mod_pagespeed ensured a keep-alive and max-age times (of 31536000) on jQuery so the 'Repeat view' was lightning fast. No jQuery download at all. The greatest factor for the initial download was Gzip, so it was dropped to 31.4KB in size. The overall time on the 'Initial view' did not change by a significant factor.
The greatest solution came in the form of the WordPress plugin, 'Use Google Libraries'. It should have been the first and not the last tool to add.
jQuery now loads in about 382ms from Google's CDN. The max-age time is also set to 31536000. Its minified and gzipped already, but point in fact its a touch larger at 31.3 KB than my initial jQuery file gzipped and minifed by pagespeed. Really, the significant difference is the Google CDN versus the Cloudfront CDN.
Overall, the site increased an average of .15 second, which sounds small but the site could never break 1.5 seconds until this plugin. and a .15/1.5 or decent 10% improvement.
This is a great plugin for anyone seeking a no-brainer solution for speed.