Since there are quality of life improvements that are often invisible at first sight, I'd like to point out a few ProseMirror hidden features:
- Typing "- " at the start of a line creates an unordered list, and typing "1. " creates an ordered list.
- Typing the '"' character correctly replaces it with the right unicode character, and you can undo that replacement by hitting backspace. The same goes with "--".
- It hints at automatic emoji insertion here: http://prosemirror.net/demo_dino.html
- Surprisingly, the keyboard shortcuts are often inconsistent across editors; ProseMirror tends to rely on widely-used shortcuts.
That said, as I mention here[0], I am most hopeful for Slack's text editor, which supports many more enhanced features -- but unfortunately doesn't seem open-source, and is currently quite buggy.
[0]: http://espadrine.tumblr.com/post/129926358821/web-editors