Earlier quoted context omitted.
I moved to firefox once 57 was released on nightly. Firefox is finally usable (in terms of speed) again and I can use it for day to day tasks.
I think I qualify as a poweruser by some standards, I tend to have 100's of tabs open and I've never left Firefox for speed reasons or others because it has held up extremely well over the years. My machine has a lot of RAM so maybe that's one reason things have been quick, and the main drive is an SSD. Is there anything specific about the 57 release that makes you feel caused the speed bottle-neck to disappear?
https://www.cnet.com/special-reports/mozilla-firefox-fights-...