The "close tab" button is in the wrong place. Seriously. Try Safari for a few days and then go back to Firefox. Tell me that it doesn't make more sense to have a "close tab" button on each tab. Heck, even Galeon had this years ago. Come to think of it, I think Galeon also had Emacs key bindings.
Agreed. Since I switch back and forth between Safari and Firefox, I caught myself clicking on a nonexistent "close button" with FireFox. :-)