I use that, it is useful for small drawings, not so much for handwriting. When using it with a tablet, maybe with some algorithm improvements, it can be as good as Inkscape.
To be fair, it really depends how you use them. Vim has a better TUI while Emacs has a better GUI. Vim is generally easier to configure while Emacs is easier to extend. Vim has more packages that extend the modal editing itself (e.g. extra text objects), while Emacs has more packages that do everything else. Etc…
In emacs you do things the emacs way. You will have a hard time if you try to fight it. This is doing something other than text editing, and therefore it is fighting against Emacs.
There is at least one collaborative editing tool for emacs [1]. I have never tried it, and I don't know how difficult it will be to make Easydraw buffer shared.
Also of note, artist-mode: http://www.lysator.liu.se/~tab/artist/