In order to do proper performance optimization, and hunt the true bottlenecks, we need to know the current performance situation as perceived by the end-users. I.e. as a minimum the duration from the user makes a request and until the response is ready for the user to continue his flow.
I understand SFDC might collect some client side performance metrics, which can be accessed by contacting SFDC support.
Still I'm curious to learn what the community believe to be the best way to measure the performance as perceived by the end users?