Firefox is great, I've been using it for the past few months. It required some customization, yes even to the source code to get it to my liking. For example you can't override CMD+P or use CMD+Shift+C to toggle the dev console so I had to make a patch [1]. I also had to develop a couple of plugins that were missing [2]. It's a joy to use knowing you're giving the middle finger to Google, your data is not tracked and stolen from you by Google and making the way for a more free internet. Sure sites like YouTube are slower to load (bc Google makes them so if not on Chrome?) but those are minor inconveniences and there are not a lot of them. So I'm very happy with Firefox and wish more people would tolerate a slight initial inconvenience and make the switch.

[1] Also made a Mac OS launcher filesystem hook to auto apply the patch every time the browser updates.

[2] Yes, I packaged and published them too.