For those who finished the game in the first week (or anyone who finishes the game, ever, in a matter of days), how often did you use fast travel to get where you were going? Since I never got in the habit of using it, I'd imagine it's must faster to finish the game if you use it to zip around.
Also, it's probably much easier to finish if you don't create character after character and discard them after level two, which is what I've been doing!