I've always found the Firefox devtools be a little less 'quality of life' like. Just my opinion. Haven't used it in a few years. But for me, I just live in devtools, you know. As most of you here, probably. Opinions?
The CSS dev tools for things like grids and flex in the Firefox dev tools are much better than Chrome's. The debugger is a tad slower if you need to prettify obfuscated Javascript but both do a good enough job at it.
I also prefer the theme Firefox applies to the dev tools, they feel more native and less like something slapped onto the browser.