Short bio: Computer Scientist, FOSS supporter (read more)
Tux Machines (TM)-specific
Daring Fireball's John Gruber has a fling with Firefox, but comes home to Safari. He praises Firefox's extensions, memory management, auto-restore of closed windows, the way it handles history, and more. But he decides that he prefers Safari because of a laundry list of small features that seem big to him.
My experience is the opposite of Gruber's: I've tried Safari several times, and keep coming back to Firefox. I wrote about my my reasons for returning to Firefox from Safari here. It's a mirror image of Gruber's post; both of us cite a laundry list of tiny features that are important to us.
To cite just one example of something I find extremely useful in Firefox: