I’m excited to see the integrated calendar, not that installing Lightning is such a big deal. I’m a huge Thunderbird fan, though. The interface is sometimes overly complex, but you can always Google around to do what you need to do.
I’m also wondering when this will hit the Ubuntu repos. I might be a ways off from seeing 78 in action! It sort of reminds me of when Gimp added a single-window mode. I was using Sabayon at the time, so I saw the new interface pretty much instantly. But when I went back to Ubuntu, I didn’t see single-window mode for months. It was like time travel.
What’s New in Thunderbird 78 | The Thunderbird Blog