I'm one of the people who switched from Vim to Emacs due to Org mode, and I've never regretted the decision. In the past year, I've used org-mode to take all my notes in class, write documents and as a task manager. All in all, the gain in productivity due to org-mode massively eclipses the time it took to un-learn vim and become decent at emacs.
You can also write and tangle code in it for literate programming purposes. You can also read-in values into the programming code in the org-file and return results to it as well.. so you could technically run your unit tests in the file and return the results in a nicely formatted org-table. :)
You just can't do that stuff with vim. I used to be a really hard-core vim guy but I eventually switched. Now I'm an emacs-or-nothing guy. :)
