I never installed Wordpress in production, this is the first time I hear about ESI and in general have almost no relevant experience, but maybe this suggestion has some worth:
ESI sounds like it would couple your web application code to your cache. This sounds negative to my ear. How about modifying the Recent Comments widget to work with an IFRAME or some AJAX? It adds another request to the server, but now both requests can be cached and compressed.
ESI sounds like it would couple your web application code to your cache. This sounds negative to my ear. How about modifying the Recent Comments widget to work with an IFRAME or some AJAX? It adds another request to the server, but now both requests can be cached and compressed.