[masfoobar]

"I stuck with FF until around 2016 or so before being compelled to switch. The performance was just very clearly worse..."

This is a fair point. Personally, I don't recall seeing a big difference between the two. Maybe there was. Perhaps it was not that bad so it wasn't as issue for me.

As for dev tools, I have been happy with Firefox - but then when I am doing web development I am testing on various browsers, anyway. So I use dev tools for all of them.

[input_sh]

Performance-wise, Firefox was significantly worse up until v57 (AKA Quantum release), which was released in 2017. I've made the switch when that version hit Nighly and haven't looked back since.

Nowadays I don't think there's a big performance gap one way or the other.

[eloisant]

The problem is that it took so much time for Firefox to improve performances and implement process per tab that by the time they finally did it, even the more hardcore geeks had switched to Chrome.