Probably the responsiveness of things. Firefox is very sensitive to DNS roundtrip time during daily use. A faster response time provides much better experience with it.
I guess that ~25% of "Firefox is slow" myth is coming from slow DNS response, if not higher.
I honestly have no idea. I observe it all the time, and note repeatedly everywhere when the discussion comes up, but never had the time to dig into the code and see how that all works.
I guess that ~25% of "Firefox is slow" myth is coming from slow DNS response, if not higher.