https://marco.org/2009/05/11/one-of-the-many-tiny-reasons-why-i-keep-using
One of the many tiny reasons why I keep using Firefox, despite Safari being much more Mac-like and much nicer in a few key ways, is the impeccable state-saving and Undo Close Tab (⇧⌘T).
I disliked the “Awesome Bar” at first, but now I’ve become addicted to its URL substring matching for autocomplete: for example, to go to the Tumblr Dashboard, I just type “dash” (autocompletes to http://www.tumblr.com/dashboard based on the substring match), down, Enter. In Safari, I’d have to type “tumblr.com/d” at minimum, and I’ve never quite been able to reliably use Safari’s autocomplete without frequent accidents.
Other reasons include XML pretty-printing (which even IE6 did, yet Safari still doesn’t) and other friendly web developer tools that, despite the recent improvements, Safari still doesn’t fully match in a few key ways that are important to me.
And it drives me crazy, because Firefox really isn’t particularly amazing. It has tons of bugs, interface quirks, and shortcomings. They’re just not bad enough for me to go without the features I use that Safari doesn’t have.