I tend to reach for Firefox's dev tools (or a node REPL) more often these days. Firefox has a much better CSS editor. I will run some dev tools in Chromium but avoid it for browsing.
Once I saw that my account was linked to Chrome/Chromium without my permission, I cleared everything out of Chrome and stopped using it as a secondary browser. My secondary browser is now a separate Firefox profile:
The big feature I'm waiting on in Firefox is live reloading/editing for scripts.
It's a huge advantage to be able to pause a script in Chrome, edit the source code, and have those changes injected back into the script. Chrome will even rewind the stack if I edit a line behind where the script currently is.
I use Firefox for all of my personal browsing and for some of my development. But I really miss that feature.
Edit: that and making it easier to debug Node from Firefox. It's still kind of a pain in that area.
I use the standard one.[1] Open a terminal and type `node` to start it or run a script with Node's debugger[2] and drop into a REPL from there. I sometimes use Slimux[3] to send code snippets from Vim to a REPL in another tmux[4] pane.
Once I saw that my account was linked to Chrome/Chromium without my permission, I cleared everything out of Chrome and stopped using it as a secondary browser. My secondary browser is now a separate Firefox profile: