Proud to say I never left. I used Mozilla, and as soon as Phoenix was released I jumped on it. Stuck with it through thick, thin and name changes. Just had a short period when Firefox became too bloated for my 256M FreeBSD laptop so I had to use Opera temporarily. But as soon as I upgraded my laptop I was back with Firefox.
For a long time, maybe still, noscript was unchallenged on FF. Something about Chrome API not allowing the deep JS blocking required. I consider JS to be the number one threat online, so I must block it by default to feel safe(r).
But really it's a no brainer to me that my web browser, my most used graphical program, should be FLOSS.