@glyph I used to run Firefox as my day-to-day browser, but I decided to give Safari a try when upgrading my laptop a while back and was pleasantly surprised by it.
The fact that anyone who cares about mobile (which is everybody) is forced by Apple's iOS policies into testing on Safari means I see fewer sites break than before, and while the privacy controls aren't as fine-grained or powerful as Firefox they still offer what I think is a reasonable baseline. Performance is also decent, and the battery-life impact is hard to beat.
I still keep Firefox installed, and I still use it for some things (especially browser-based games), but I'd say my usage of it has dropped probably 80% or more.