Quantum is coming!
Did you stop using Firefox because of speed? They've worked hard to fix that, and it worked!
Tomorrow you should give Firefox another shot!
For normal people: https://www.mozilla.org/en-US/firefox/quantum/
For nerdy people: https://hacks.mozilla.org/2017/11/entering-the-quantum-era-how-firefox-got-fast-again-and-where-its-going-to-get-faster/