i ve got the same experiences with mod pagespeed.. finally its slower than w/o mod_pagespeed. its nice to have images rewritten and so on, but it does not make the site running faster by now. tested with apache benchmark, yslow and so on. IÂ´m not sure why but pagespeed can truley slow down things – a lot of apache processes can happen and so on.
so i turned it off by now because optimation on serverside / vhosts without mod_pagespeed seems better to me.
to wp super cace
i tried the cdn option but die result was, that link to posts were rewritten to and didn`t work anymore.
have a nice day and thank you very much for everything!
one of your fans from germany