Firefox has almost imperceptible jank, but it is there if you squint. Since forever I have a test that firefox always fails at: on first load, or if you haven'

Firefox has almost imperceptible jank, but it is there if you squint. Since forever I have a test that firefox always fails at: on first load, or if you haven't right clicked in a while, the context menu takes a perceptible amount of time to show up fully, and within this very short amount of time, you can visually see the menu options cascade out as the CSS engine finishes laying out and rendering the context menu. This kind of jank still happens on latest firefox. It's little things like this that make it feel unpolished. I never observe this behaviour on Chrome.