5 stars: They call it a beta but since I started using it a year ago (galaxy s8) it hasn't crashed once. I put it on my tablet and it's great there too. It's faster than chrome and my infosec buddies tell me firefox is also more secure. It only took a couple days to get used to and now I find google-browser behaviors annoying.
5 stars: Firefox is the only browser I trust. I do not trust Google Chrome!! I am pissed off at the developers of Firefox for removing the about:config from normal Firefox for Android and making me use Firefox Beta for Android! I feel Firefox on PCs and Firefox on android, there should be no difference between the two of them!!!
4 stars: I've been using this since the beginning, and despite some amazingly bad moments, the current release is stable and has a few nice features. One thing that is rapidly becoming a deal breaker - the inability to choose our own fonts. There are only so many pages of Times New Roman I can look at before my eyes start to bleed - an override with a sans-serif option would be helpful. I can do this in Windows, why not Android?
2 stars: Wow, FF is getting steadily worse! Zooming pictures no longer works. Scrolling is buggered. Somewhat related: if the menu bar is hidden, link clicks don't register. Basic universal functionality is STILL missing! Pull-down to refresh should have been there from day one. I've been using FF since M0.7, and lately it feels like they're losing their way.
2 stars: The only good thing ...