Interesting I have a mental picture for users of the following:
Safari - Fasion Concious, Slightly pretentious and loud, likes to be seen at parties, maybe owns a sports car.
Firefox - Young and thrusting types who like to rebel a little (not too much though)
Chrome - Wouldn't be seen dead running Safari.
Opera - Well, its not your Dads browser, but ..?
IE - Sad old geeks who are more concerned with other things( as long as it gets the job done).
I think FF is young and like to cheat hehe. I mean, the cheater on Facebook games, who grabed all the goodies right away are the greasemonkey cheaters. Ok, I used a few times, but, normally I don't cheat.
Chrome, not too much experience, but I know it doesn't freeze tab, unlike FF and IE.
IE, very user "unfriendly". Haven't tried to compare with Chorme, but, it accept gifts on Facebook faster than FF with multiple open in new tabs followed by accept button clicks. And Flash is slower on IE8 than IE7, IE6, and FF.