I'll disagree. There are too many regressions in the new UI (FF/Android Beta, 80.0.1 over regular FF/Android 68.0). I use FF everywhere exclusively and that includes on my tablet, where keyboard and mouse shortcuts are totally missing; not even ctrl-T for a new tab. The UI breakage and uncanny valley only seemed to increase when I checked out Nightly to see if things got better there. Also, while I understand why a phone friendly layout takes top priority with meager dev resources, the loss of the "desktop-like" layout on the tablet is kinda painful on a tablet. A cursory search about these things is that Mozilla simply needs to focus on the major points first and edge cases like tablets will come later.

On the plus side, the webview capability is wicked cool and I have several PWA's "installed" to my home screen. I'm really enjoying that.

I understand things will improve with time. It's just a bit of a rocky experience right now.