Have you tried using it recently? The quantum rewrite they released last year is incomparable to the previous releases. I use FF at home and Chrome at work and I can tell you that there is no noticeable difference in performance. The only time you'll notice the difference is when you use google apps that are written specifically for Chrome, but I personally prefer to avoid trusting the biggest adtech company in the world with my personal data. Plus, FF supports vertical tabs, Chrome doesn't.