Using this plugin on my site in Hostgator, and it makes a solid improvement in load times. Works great with Amazon Cloudfront as a CDN, but am getting a warning from PageSpeed that browser caching isn't being utilized.
I tried deactivating W3 and reactivating WPSuperCache, and it does leverage browser caching. Switch back to W3 and same problem (no browser cache). Tried switching from Disk (enhanced) mode to basic with no effect.