Things have been working great! I have reduced the load time for my site by 70% -- however -- I am stuck on some reports that I am getting from YSlow.
In the "Browser Cache," I have ensured that I have "Set expires header", "Set cache control header", and "Enable HTTP (gzip) compression" all checked. And in each of the three sub-sections, I have the "Cache Control policy" set to "cache with max-age," and the "Expires header lifetime" set to 604800 for Media, CSS and JS files.
But I am still seeing reports indicating that things are being delivered without expirations -- and that the system is not delivering gzipped versions (and yes, they do exist).
Any thoughts on what I should check next?