User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:18.104.22.168) Gecko/2009060308 Ubuntu/9.04 (jaunty) Firefox/3.0.11
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:22.214.171.124) Gecko/2009060308 Ubuntu/9.04 (jaunty) Firefox/3.0.11
Although it is a known issue that many addons will slow down Firefox, there is no official tool for measuring the effect that individual or multiple addons have on Firefox. Internet Explorer 8 now come with this feature, for measuring the load time and other Extensions' effect on the browser's performance. Therefore, I request that Firefox also include such a metric.
This will help encourage responsible Extensions' development, help users troubleshoot problems, and help users configure Firefox for performance as well as features.
I second this; Chrome even comes with a task manager that shows how much memory, CPU and network any part of it eats.
Right now, it's way to complex to figure out why FF suddenly gets sluggish.
I third this lol; it is a very good idea. There are many times when firefox seem very slow one day then fine the next. I would like to know why!