The prioritization parts of Quantum DOM have landed. There is some work around preemption that still needs to happen. We should have a post talking about this coming out in the next few weeks.
- when you swipe fast, the page only scrolls by like 30%, instead of scrolling by 200% like in Chromium browsers. Basically it's impossible to quickly scroll a long page on Firefox (maybe it's configurable somehow in about:config?)
- when you long-press a link, it takes like 2-3 seconds for the menu to open. As I "open in new tab" by default, this quickly adds up.