@billstclair there are just too many features I use so often that I miss. But the E is for extensible right? Who really cares whether you hit y or alt-w or p or crl-y?
O was thinking of "EMACS: The Extensible, Customizable Display Editor" https://www.gnu.org/software/emacs/emacs-paper.html
Escape-Meta-Alt-Control-Shift is what I think of... :) I still use both Emacs keys as well as Vim commands at the same time. and if I do C-Z I am back in emacs mode anyway.
But I use Vim keys in the browser, in Eclipse, in Emacs.. So yes when you get used to a set of commands.
So do you use Hemlock and Cocoa?