I know of one issue with Firefox when you are using a scaled resolution. It absolutely destroys battery and performance for me. I _think_ it has gotten better with the latest versions but the tickets are still open.

https://bugzilla.mozilla.org/show_bug.cgi?format=default&id=...

https://bugzilla.mozilla.org/show_bug.cgi?id=1407536

https://news.ycombinator.com/item?id=17365510