Fast to start. I use Emacs for programming but if I have one single file, like a config file, that needs a quick edit, use vi(m) because otherwise I have to either:
1. Go to my open Emacs and navigate to the location of the file needing the quick edit 2. Open a second Emacs instance, and hope I don't lose the desktop settings for the "real" instance.
Especially if the file needs to be edited sudo.
If there is a way to open a file in the existing Emacs instance without navigating, I would be glad to use it except for sudo.
The way that "firefox some-local-file.html" will open up that file in the existing Firefox instance.