i would say folks, (speaking from non-pda vi use) if you know how to use it, then vi can be the best editor ever.
it has scripting and excellent syntax highlighting.
the reason it is on every unix system is because it is so so small, compared to emacs vi is absolutely tiny,
if you are a unix user, even if u prefer emacs, its always good to know vi well as sometimes you will have such a broken system to fix that the only thing that will still work is vi.
vim is alot easier than vi, (vim can emulate vi awell)
vim is simply vi with some more clever stuff that you will never see (often) built in.
seriously, (on a non-pda) once you get the hang of the commands, its great.
[insert] - switches you between insert and replace mode
[esc] - puts you in command mode
[esc] v - puts you in visual mode (for copy and paste etc)
[shift]aa - move between windows
- command mode -
:q # quit
:q! # quit without save
:w # save
:wq # save and quit
:u # undo
:split file.txt # open another file in a vertical split window
:read file.txt # read in file.txt at the current location
:-)