Hey,
I saw the other day a performance audit that Paul Irish did for the mobile site of reddit.
It is a great audit and a great example of how to do a performance review of a site, I encourage all to carefully read it as we are going to have to do something similar in the following sprints in order to enable us to do more concrete performance work on the mobile website.
https://github.com/reddit/reddit-mobile/issues/247
Awesome stuff.