I use Chrome. When Chrome first came out, I decided to give it a go but it was somewhat buggy in the beginning and crashed a fair amount. So I was using both FF & Chrome. Later on I just ditched FF. I never really used any addons on it so the reason I ditched FF for was it was faster and more smooth.
However, nowadays I can't login to some email accounts (like hotmail, mail.com etc). It shows a page full of cookie values for some reason. It works fine for IE so I know it's not something malicious. Dunno, I guess I'll wait for an update.