awesome. I have been using varnish for a while now and it's just awesome. The VCL configuration works like a charm and is very simple.<p>ESI is really cool and can be easily integrated as a normal include with the common frameworks. For example, cached file including when developing and ESI tags when production and stagging.
Having ESI is very good to cache and distribute in parallel different parts of the page, that can have different CPU usage. Also it's really good to cache stuff even when the user is logged in.