I have both--the Passporter is very good, the Birnbaum is disappointing. Not much critical or inside on Birnbaum's, could have been published by Disney from the look of it. As for comments that you can find that you can learn as much from the DIS board as the Passporter book, that might in fact be true, but it is all organized and handy and portable in the Passporter book--the better for DW, who is not a patholigical internet junkie to use for cruise prep.