Gylfe: Firefox is trash. I used it for years and put up with the constant bugs, but i switched to duck duck go and no more issues.
Uh? Well, I guess you talking about mobile?
I gave up Firefox as primary browser when they pushed auto-updates. I'm still using it and is good enough, everything seem to just work, to the best of my knowledge. It's the only browser on Windows that seems to work as good as Chrome with touch inputs.
Palemoon is bit weird on Youtube videos, slow to load and kinda locks the browser for a few seconds. It's good overall, lightweight and fast but some users may find it annoying and outdated. I believe the last time I installed Palemoon that, in order to install uBlock Origin add-on it needed some weird steps.
Vivaldi is nice but there's some quirks. If you like to tweak the browser to your liking, this is the one!
Also, installing add-ons, like uBlock needed the Google add-on store.