For what it's worth, I've had a great experience with firefox for the past year (since quantum convinced me to give it another chance). All though, it recently basically factory-reset itself. Signed out of sync, extensions gone, custom settings gone. Any one else have this happen? It's also got a weird memory leak, which I think is related to the pdf viewer. Never really checked in detail or tried to measure.
I basically can't trust them anymore.
[1] https://www.theverge.com/2018/5/7/17326184/firefox-ads-spons...