I don't know if it's as applicable for a vim user, but as an emacs user I really appreciate having access to the same tools I use to edit all of my other text:

I don't know if it's as applicable for a vim user, but as an emacs user I really appreciate having access to the same tools I use to edit all of my other text: the same search, the same dictionary, the same completion engine, the same Org-mode keybindings (so that I can save myself a note or TODO as I'm in the middle of writing), the same … everything. Honestly, every programme other than emacs is a distraction.