So I tried moving off Chrome 68 to Firefox 62 today, and it's quite noticeably slower than Chrome. Here's a couple GIFs from Gmail to show what I mean [1]. I start both of them at the exact same frame that I release the Enter key, so you can see exactly how much longer Firefox takes. Notice that it takes longer to render the Star/Important icons, too (including the very noticeable flash of placeholder text), not merely load the page. The situation gets even worse when I install extensions, but these are on profiles that have already visited this page, but which are otherwise fresh. (Edit: Trying it on Facebook with a clean profile now. I realized I hadn't cleaned the profile before testing non-Google sites.)
So I have to say, I'm really baffled. How are people switching to Firefox and finding it to be so fast? Is this speed difference unnoticeable for everyone but me?
UPDATE:
On Facebook, I see similar speeds without extensions. However, when I browse with my usual extensions, Firefox is again noticeably slower -- even though the extensions in Firefox are literally a subset of those in Chrome. Are other people's experiences similar?