Was a user from the Phoenix/Firebird days with the "unzip it somewhere" fancy installation process, used it for almost 20 years, and then switched to a Chromium-based browser due to perceivable speed differences.
I wasn't running benchmarks to confirm my suspicions or that performing some action was x milliseconds slower in Firefox or anything. But when you're using something all day, every day including as part of your job, it is easy to get a feel for.
With these multiple reports recently of performance work, along with real-world metrics ... I'm thinking of sticking with it for a few days again. If I don't notice the difference, or it actually seems faster, I'll switch back.
I want to switch back, because we need to ensure there are alternate browser engines, and I don't want standards committees to turn into "this year, Google deems we shall be doing the following" sort of events.