Haven't seen one of these around in a while and I recently finished up a browser switch myself recently.
My go-to browser is now Firefox Developer edition on my desktop and Chrome on Android, the full breakdown is below
Home: Firefox Developer Edition (70%), Firefox (20%), and Chrome (10%)
Work: Chromium (65%), Chrome (20%), and IE11 (15%)
Phone: Chrome (70%), http://www.enricoros.com/opensource/swe/ (25%), Firefox (5%)
Before this year I was using PaleMoon as my default browser. I switch from Opera to Pale Moon when Opera stopped using the Presto engine for Webkit/Blink. I chose Pale Moon because it had x64 builds and would use a different profile than Firefox (I use Firefox for connecting remotely to work through SSH tunneling and stuff).
Over the past year or so, Pale Moon has been making a lot of changes that made it slower, less compatible with upstream Firefox, and less stable. Also, it was very obviously failing to stay up to date with web standards, something that http://news.softpedia.com/news/pale-moon-devs-ponder-dropping-current-codebase-and-starting-from-scratch-501920.shtml. The final straw was near the end of last year when I wanted to start playing with ES6, I found out that Pale Moon had a complete failing grade at ES6 (launched a test on the version I had installed and it only was 20% compatible). That was unacceptable to me. Looking at how things have gone this year for the browser (forked Gecko engine, developers facing serious issues), I am glad I decided to switch.
So I went in search of a new browser. I still wanted 64-bit and for it to not mess with my standard Firefox profile. Firefox Developer Edition fit the bill perfectly. Also, it feels good to support an open source browser that, for the most part, cares about privacy and open web standards.
At work many work-related websites only officially support chrome and IE, so I don't use Firefox there. On my phone, I'm an android guy so Chrome is my go-to. I have CAF Chromium on there for when I need to use a browser with adblock, but I'm a bit afraid to be too reliant on it, as they don't seem as readily updated. Firefox on my phone is there mainly for the same reason as my desktop: browsing through an SSH tunnel.