The test results was quite interesting. My clients Varnish+nginx+php-fpm cluster was actually faster than googles service in 3 out of four tests.
The grid with the results below says it all.
| Varnish nginx+php-fpm | Googles page speed service | Difference | |
|---|---|---|---|
| Page Load Time | 2.720s | 3.157s | +0.437s (16.1%) |
| Start Render Time | 0.897s | 0.706s | -0.191s (21.3%) |
| Repeat View Page Load Time | 1.381s | 2.264s | +0.883s (63.9%) |
| Repeat View Start Render Time | 0.272s | 0.392s | +0.120s (44.1%) |
This is just one of the installations I have done. Results vary depending on what type of content you store. My clients content is a mix of static and frequently updated content.
A perfect example on a properly optimized website.