Today both coworkers working in my room switched to Firefox. I didn't do much to push them to switch. They use to work with IE replacement and they new I used ff - but they use to say, that ff is worthless. I did not answer - My coworkers are tech savy. Today they were bitching about the inability to force new window to be tabs : I showed them how they should tweak their prefs to have it (meaning showing them about:config). I'm pretty sure they'll stick to ff from now on, and when our third coworker comes back to work, he will also switch, just because the other two have.
The only thing we can't easily do is download extensions because getting extensions requires and encrypted connection.