Three days for one playthrough? Huh, that's not bad... Although there are almost half a million words in the game right now. Guess that's probably about how long it takes. Which is funny, I've always wondered how long the average playthrough takes now. I'm mostly busy testing and fixing things while playing the game, and that's surely not the same.
By the way, it's impossible to see all events and scenes in one playthrough. Some things are tied to Origins, some to Abilities, and some to choices made. Just a mention :)