Low latency with a handful of pingdom monitoring nodes sitting in data centers does not necessarily translate to the "fastest repo on the web". We've tested CloudFlare since their launch using thousands of real users, and based on that testing performance tends to be on the low end compared to traditional static content CDNs. CloudFlare is more of a website proxy than CDN. By assuming full control of your website DNS, it stands out more with add-on features like security. Here is a link to some real user performance analysis I've compiled for various CDNs including CloudFlare:
http://dl.dropbox.com/u/20765204/feb12-cdn-report/index.html
I have similar experience with CloudFlare. The Speed just isn't there. Most CDN perform MUCH better then them. I would love to pay to even get faster speed. But that is not the model they decided to work on. I hope they will have more speed improvement coming in soon.
