I believe that too much is lost in the quick-editing available on the computer, so usually I write on paper all that I want to and when I have that edited, go to the computer to polish it.
The computer-only style makes it too easy to get rid of passages or phrases that might not fit where you wanted originally, but work out great later.
To also be blunt, it makes for a lazy writer who relies too much on spell/grammar checking tools instead of actually learning them.