I don't know about you, but I spend my workdays fully immersed in two specific things:

1) Terminals (gnome-term, mostly, but sometimes xterm)
2) Browser windows (Firefox2, almost exclusively)

The terminals are always great, never giving me hassles or whatever. But the browser windows...something had gone wrong from FF1.5 to FF2 (though my experiences with FF3b2 at home have shown some promise). Loading pages kills memory and cpu, opening new tabs takes forever, and pages with flash or javascript...forget about it if you have something to do in a hurry.