I've installed the Lite Cache plugin and removed the W3C (after I found that it slowed my site down).
I'm very pleased with the result. (Here is the WebPageTest for my Home Page, after this installation)
My question is the one of a rookie (no one is perfect) : What should be the average cache duration for a small site like mine?
For the moment I've set it to four hours. Is that ok?
And even if the result is quite good I wonder why the WebPageTest, (see above), still shows Grade D?
Thanks a lot. In advance.