Having switched to Zen Browser, something I miss with Firefox was its stability. I find myself looking up Zen browser bugs and workarounds too much. This is the 2nd or 3rd time I’m downgrading Zen versions due to a bug in the stable version, I never had to do so during my years on Firefox. Devs on Github making an app on their free time have can’t spend as long on QA as a multi-mullion dollar organization.
I never have, but I typically run what’s packaged by Debian, which packages Firefox ESR.
I’d imagine that if one runs nightly builds or something, one would hit some level of regressions.
I run nightly, not exclusively but pretty close, and I must say Firefox’ nightly builds are pretty damn stable in my experience. For sure, there are situations where some feature y is clearly unfinished, but it’s super rare to face a situation where I would even need to think about working around some issue - such game breaking issues just don’t happen too much at all. Usually, if a build is found to be truly broken (like crashes very often etc.) then nightly updates get paused. I can remember maybe two times that I’ve had to revert to previous build in over ten years because the I had received an update before updates were halted.