"mod_pagespeed" Someone tested it already?

Is there any difference between the page with “mod_pagespeed” ON and OFF?
I can ask my hosting provider to turn on mod_pagespeed. But is there any acceleration?
My sites has PageSpeed score 94-97.
(sorry for my English)

Your score is already good and i don’t think you should use mod_pagespeed, it will add additional processing and will consume server resources.