I am not a Firefox lover. It's Opera all the way here. When I use Firefox I'm constantly missing features Opera has that Firefox doesn't, or that you need Firefox extensions to get.
I like IE much less than Firefox, though. Unfortunately, I still run across Web sites that don't work with anything but IE. I usually send a complaint to the Webmaster. Maybe if enough of us do that, they'll drop the proprietary stuff.
--GrannyGeek