I switched in late 2017 when they released quantum or neutrino or whatever they called it, a huge performance release.
As a backend dev and security focused eng I have little reason to test drive changes in all browsers.
FF has been smooth and stable for me across desktop OSs. Having no reason to alternate between that and Chrome, I’ve been confused by people saying it’s slow.
It’s been, to my memory, a flawless experience for 3+ years.
On the flip side, Chrome is a spy app, and a cognitive perception of web devs it’s faster does little to move me to use it.
It was a little wonky when they first released it.
Sync has worked great across Mac, Windows, Linux, and I-devices for me.