I'm suggesting ways to find such numbers, but I don't have access to update the source code.
I agree that it would be useful to get numbers. Why don't you prepare and test your patch and post it here (or get commit access from Magnus).
I think it would be best to simply report the times in an HTML comment attached to every served file, as you suggested earlier. This way we can all perform our own tests from home and no artificial bottleneck slowdowns are introduced (which could occur if the time data were logged in a central file).
Axel