While serching in google for more tweaks in FF, I came across this thread in a forum.
It's rather a large thread as stated it his opening paragraph -
While it is not complete, it is one of the most comprehensive resources available on the Internet.
I've also found a similar thread here which relates to the pipelining issue but this time the tweaks have been separated into sections for different computer/connection speeds.
This could be why some ppl get a good increase in speed and others not so.
Just a little bit of trivia for you as well..........
In case you haven't heard, Firefox is rapidly gaining steam as a free replacement for Microsoft's own Internet Explorer browser. OneStat.com, which measures Web behavior in 100 countries around the world, reported on Nov. 22 that IE had lost 5 percentage points of market share in the past six months, dropping to 89% of browser users. Firefox and its predecessor, Mozilla, are up to 7.35% of users. The foundation says 7.5 million people downloaded Firefox 1.0 in the month of November.
Quote taken from Windows Secrets
Hope you all find this helpful.