Firefox-first definitely seems to be the way forward for web developers. We fell into the trap of Chrome-first and ended up having to fix everything for FF and IE, creating a lot of work. Soon discovered that if we just developed for Firefox everything would generally "just work" in the other browsers.
I generally also find the devtools to be better but both Chrome and Firefox have years-old bugs involving source maps, breakpoints, etc. so I end up cycling between the two during any given day.
