Menu Bar
Hate that SuperNova update changed many of my settings and views that I have fine tuned over many years of using Thunderbird. Have fixed most, can tolerate a couple I couldn't, but I absolutely hate that the File/Edit/View/Go etc Menu bar isn't at the top where its supposed to be.
Besides annoying to look at with every other Windows software standardized with this menu bar the uppermost, its also a matter of moving the mouse and real estate - ie: if your checking your inbox and want to reply, or junk it, or forward it we now have to travel further to the top of the page.
And as well, the quick filter search bar I always liked in the Thunderbird Menu bar is now only available across the top of the message column pushing emails off the page by taking up more real estate than it used to.
Sorry Thunderbird/Moxilla but its a stuff up. There was nothing wrong with Thunderbird the way it was - reliable and standardized, and everything could be put in a place to best suit the user.
Opaite Mbohovái (3)
There are several posts on this forum about moving the Menu Bar, such as:
https://support.mozilla.org/en-US/questions/1422908
It's also possible to have the Unified bar and the Menu Bar on the same bar.
shortly: Give us back the standard menu bar!