I do all of my personal browsing in Firefox, but I have to use IE for work. Firefox doesn't play nice with a lot of Javascript stuff, plus a lot of the Flash stuff we've got, and when you mix the two it starts getting really ugly. It's a big step forward from IE6, and an adequate alternative to Firefox, but not completely up to snuff.

Besides, I was more disappointed by Firefox 2 - it wasn't much of a step up from v1. Mostly just a strategic move on their part to counter/ride IE's wave.