http://www.theregister.co.uk/2017/11/15/mozilla_interview/
 
The comments are worth the read.  Some are sticking with older versions since many add ons will not work.
One of the best comments was about how browsers can't be customized to your own taste.  I still like menu bars on browsers which I why I don't cozy up to Chrome.  It seems too many things are resembling phone apps.

Mine just updated to the new Firefox Quantum (57) Lost 2 add ones, but one is being updated so that's fine. Couldn't stand the sharp square corners on the tabs, so that was the first thing that had to go, it was an easy fix, create a folder, create a file, copy paste contents and restart. Anything else is just small things that will disappear as I get used to the new one and forget the old. But the main thing is it is smoking fast compared to the previous version, it is very noticeable, fast and smooth, they mentioned it's speed in the blurb and I thought yeah yeah, but it was true. Onward and upward.
 

kitekrazy1
 
I still like menu bars on browsers which I why I don't cozy up to Chrome. 

 
Menu bar is still there/available

Anything else is just small things that will disappear as I get used to the new one and forget the old.
 

Those little niggles are now fixed (just forgot how to do it)

Firefox Quantum is certainly fast and smooth. I didn't like the defaut layout, but that was an easy fix using the Customise 'drag and drop' system.  

Songroom
Firefox Quantum is certainly fast and smooth. I didn't like the defaut layout, but that was an easy fix using the Customise 'drag and drop' system.  

That's what I forgot how to do .
 
Really my only issue was the sharp square corners on the tabs, thankfully back to the nice curves now and all good.

My only complaints so far are the loss of NoScript (but the devs say they are only a day or so away from releasing the new one so I'm pretty happy about that) and FlashGot/DownloadThemAll and how some things like browser history in the menu have been moved around and take more steps to get to. Otherwise, everything is running smooth.

DownThemAll is being worked on. I mustn't understand about the 'Browser History' in the menu, as mine is axactly the same as previous.

TerraSin
Some things like browser history in the menu have been moved around and take more steps to get to. Otherwise, everything is running smooth.

If you 'left click' the menu at the top right hand side of the browser and select 'Customise' you can add / remove items from the 'more tools' (>>) menu using 'drag and drop'. You can also drag existing items (such as the browser history, home and refresh icons)  to new positions.
 

 
Don't forget to click the 'Done' button to save the settings.

TerraSin
My only complaints so far are the loss of NoScript (but the devs say they are only a day or so away from releasing the new one so I'm pretty happy about that) and FlashGot/DownloadThemAll and how some things like browser history in the menu have been moved around and take more steps to get to. Otherwise, everything is running smooth.

No Script Suite Lite works perfectly in Quantum.

 

I was using Chrome and still mostly do by force of habit. Recently the  software I use to remote access systems wouldn't load correctly. Turns out a Chrome update was the problem. This has happened twice within the last month.
 
Firefox was the only stable browser to use with it until they could figure out what the problem was. If Chrome fails to load a program properly, Firefox has never yet failed me and seems more stable overall than Chrome.