I think that's what it comes down to: vi is easier to learn, but emacs is much more powerful. My current job involves using a very esoteric in-house language, which doesn't have any IDEs or even Notepad++ text-formatting extensions; I'm thinking about learning emacs, which can be programmed relatively easily to become little less than an IDE for it.

(Speaking of, behold another holy war: IDEs versus command-line development...)