I really like Firefox myself, tried it once before while it was still beta and didn't care for it. With all of the security holes in I.E. I decided to try it again. Once you get used to the tabbed browsing and learn some of the keyboard shortcuts, it would be hard for me to quit using it. Here's a link for the keyboard shortcuts: http://www.mozilla.org/support/firefox/keyboard.html
You can also get optimized build for your computer, AMD, Intel P4, etc. at this location: http://www.moox.ws/tech/mozilla/mdefs.htm
I'm using the M4 build and it does seem faster.