Great to see Mozilla consistently improving devtools in Firefox. I have been using them over Chrome for a while now, hope it gets to a place where most devs start using FF again for debugging web apps.
For example, I'm running Nightly, and the Dev Tools>What's New tab says the "Debug Variables with Watchpoints" (break when a property is read/written) feature is in Developer Edition (and presumably not in Nightly or the Release channel).
Finally! This was the main reason to develop on Chrome instead of FF for me. The rest is almost comparable with Chrome DevTools for everyday web development.