plz search around, there are numerous discussion about this already.
I would advise u to try them both, maybe firefox's goodie don't affect you, maybe you don care about safari's advantages, nobody's experience can replace your own.
I don't agree with clevin on much, but I do agree with his advice to you. There are numerous Safari vs. Firefox threads here already. You are not going to add anything new by creating a new thread. Click the Search drop-down menu immediately below the Mac Rumors/Page 2 tab above. It is between New Posts and Quick Links.