I was so excited over having this one installed, as I badly need any help I can get to make my site work faster.
The installation went well, files were correctly updated, a few pages were cached. I was logged in so I didn't see any change myself. However, a little bit later, I logged off only to see that the site's layout got completely messed up and an error message was displayed!
Here's a screenie of what resulted: AdOperationsOnline.com with WP Super Cache enabled
Basically, the sidebar was thrown off at the bottom, and the error message you can see underneath the header was also displayed at the very bottom.
I disabled the plugin and things went back to normal, thankfully, but this was a major scare!
Quite bummed... I wouldn've so wanted for this to work.