Well, vi is the editor I use 2nd most (after Emacs), but I use nvi nearly as often as I use vim, and I avoid the vim extensions (except the useful :help).
I imagine changing vi to vim would be a bit like changing Emacs to GNU Emacs.
I imagine changing vi to vim would be a bit like changing Emacs to GNU Emacs.
There's also Steve Youngs' SXEmacs (a XEmacs fork), which is probably the most well-developed of several efforts to extend Emacs to be a window manager.
vim pros: syntax highlighting is often nice (though when I really care about highlighting, I usually use Emacs), vim's :help is very nice, vim is usually installed
nvi pros: the small TCB I prefer when I'm root (`find /usr/share/vim -name \*.vim | wc -l` just gave me 1103 results, including hundreds of scripts that might be run without me explicitly asking for them), no splash screen, avoids the autoindenting that is often irritating, bound to vi on FreeBSD
I can't say nvi vs. vim efficiency has been an issue for me, but it has been for some people ... http://www.galexander.org/vim_sucks.html