Latest Firefox browsers suck, I'm curently using firefox v53.0
The only reason i use firefox is because of the custom buttons addon.
NO CUSTOM BUTTONS THEN NO MORE F'iN FIREFOX FOR ME YOU HAVE BEEN WARNED MOZILLA. FIX IT NOW OR I'LL BE PAYING YOU A VISIT.
following are my personal reasons:
1. version 57 custom butons addon not working
2. freezes crashes all the time on all my computers..
3. version makes no difference since maybe version 26.
4. uses up too many cpu resources for no reason.
5. takes up lots of ram.
6. unstable.
to firefox developers fix it or fu
you say "security updates", I say security holes.
and finally screw your updates.
Opera browser is much more stable
...
https://www.youtube.com/watch?v=zlKTDD2Eh8w