Gavin - what kind of evidence do you need in order to take this patch into consideration? I haven't had the resources to perform proper load testing on it, but jrmithdobbs provides encouraging anecdotal data that suggests that the patch does indeed improve performance significantly.
The original implementation was synchronous and blocking: it allowed only one connection to be processed at once. My patch improves this behavior by rewriting the connection handling code to use asynchronous IO - enabling many connections to be processed at once. It should be clear why this improves performance.