>>913018 (OP)
>spyware
yes
>incredibly slow
All firefucks and its derivatives are or have been incredibly slow. Chromium is significantly faster but I'm wary of using it or its derivatives because jewgle. Falkon has a lot of highly annoying bugs (fullscreen videos sometimes hang the browser irreversibly, etc.) but otherwise it's fast and generally ok to use.
Only links and elinks actually work well on my computer. If only I could use imageboards properly on it...
Take in mind that my CPU is always 100% occupied by crypto mining, so a browser that works well under those conditions is truly a good one.
>add ons
Firefucks will never again have good addons. SJWzilla killed the backwards compatibility and for that reason no individual addon developer will ever put any effort into their work because SJWzilla has set a precedent for not maintaining backwards compat.
>IceWeasel
Iceweasel is exactly the same code as firefox. Debian uses it because the Firecucks logo and branding are proprietary.