When it comes to FireFox new isn't always better. I had it installed for about an hour and gave up. The window controls in the upper right corner never did show up and there where other problems. I really don't understand this update cyclle of every two weeks to a month and the so called update breaks things that worked.
My opinion is that if it doesn't work out of the box it's still in beta.
Restored my back up to Pale Moon at least when it updates nothing breaks. Maybe in a few months I'll give it another try but it will probably be up to v43 and still be a beta on release.