But couple of your annoyances can be fixed rather easily:
1. Get back the toolbar back: View (or Alt-V) - Toolbars - Menu Bar
2. To clean recent history: Ctrl-Shift-Del will give you the clean recent history dialog box. It can be accessed from toolbar too: History - Clear recent history.
Weird that the only way to get to that menu is through a toolbar that's not visible by default.
What's unusable about the new tree style tabs? I use it constantly.
If you want old greasemonkey scripts to work without changes, use violentmonkey.
There must be a bug with the new greasemonkey that I can't find the editor either. Use violentmonkey for that too for now.
I'll grant that the new responsiveness of FF makes TST feel much better. But there's one thing that's constantly giving me headaches. I don't feel like the highlighting given to the currently-selected tab is in-your-face enough, so that I'm always scanning up and down the tree trying to see which one it is. The other formatting options it used have were nice, but being able to at least make the selected tab's title bold was a big deal for me.
I realize that this is technically possible in the new regime via userChrome.css. However, the element classes are completely undocumented so I have no idea how to accomplish it.
Before FF57, I was able to set the font and background color for tabs depending on their status (current, inactive, unread, etc.), and that's what I want now. IIRC, this was actually a feature of Tab Mix Plus.
It's clear that this is still possible even without TMP, but requires putting code in userChrome.css. That would be fine with me, if I could just find any documentation on what element classes (or whatever would be the most appropriate selectors) I need to reference.
document.querySelector('#sidebar')._contentWindow[0].document.querySelectorAll('.tab.active')[1] https://github.com/piroor/treestyletab/wiki/Code-snippets-fo...
With tree style tabs I didn't realize there is a CSS hack to remove the top tabs.
Things that bother me on desktop developer edition:
Android (Mobile) Quantum takes forever to load pages. As in 5x-10x longer than Android Chrome. Some things like videos from twitter simply don't load at all. Some websites no longer load. Cannot enter data into some text boxes. But don't take my word for it: https://www.androidauthority.com/mozilla-firefox-quantum-and...Unfortunately, on desktop I'm stuck between this new FFX and Vivaldi. On mobile, I already switched to Brave even though it's terrible because you can't easily google for selected text or select a part of a paragraph easily.