Nic Windley on "[Plugin: W3 Total Cache] disk: enhanced + query string = slower page load"

I've been running tests on landing pages and whilst tracking campaigns I've noticed a 2 seconds page load time difference when adding a query string to the URL for tracking purposes with disk: enhanced compared to disk: basic.

Even though the page contains no dynamic content it actually serves 2 seconds slower when using disk: enhanced than running disk: basic.

http://wordpress.org/extend/plugins/w3-total-cache/