Firefox will never be beaten by IE. Even if it is marginally faster in 'some' tests.
FF is just so incredibly customizable with it's themes and add-ons. 'Ad-block plus' to name but one. What is internet advertising ?
With that plug-in alone FF beats IE in one fell-swoop.
Not to mention Greasemonkey and it's scripts.
Firefox really feels like it's your own browser. Something IE can never be.
Just my opinion...