I have multiple browsers at hand utilizing a Linux operating system. They all work pretty well, but require the usual level of concern as far as privacy settings and cache clearing goes. I have no issues with Firefox at all, I simply prefer Epiphany when browsing on this site; it is a Debian based browser that is available on my Mint platform utilizing the Cinnamon desktop.
It's all a matter of taste and personal preference. Even back in my Windows days, I hated Internet Explorer and preferred Netscape Navigator. Seeing as Firefox is basically a Mozilla based free browser; it's Open Source software and is constantly improving. I have yet to trust the Google Chromium browser, but see no problems ahead; I just know that Google is a pretty big player in the world of search engines and I equate that with the privacy issues revolving around safely surfing the Web.
Sorry but I don't know anything about the Linux system at all, sadly. I'm just trying to help you guys out of them problems with the slowness.
I only know the Windows system and if you guys have serious problems with your Windows system and Internet, I can recommend that you go and get some help here:
https://www.landzdown.com/ They knows alot about solving them problems there! Try to get in touch with Corrine there.
Corrine knows alot about how to fix them problems.