This guide is barely a guide, all the information in it was available on the web before the game was out. All it offers me in terms of content, is the orange and white bar that says "Kingdom Hearts: Dream Drop Distance" on my bookshelf next to my KHII, Days, and BBS guides (I have KHI, and Com guides, but they aren't on the same shelf as I organize by Color, than name.. yeah I know weird...)
Imo the Days and KHII guides were the best. The KHII one because it told you bits and pieces about characters and who they are/were in their original production. And gave a nice list of abilities drops and collectibles.
The days one because it not only gave info on the story but also on the missions and challenges. As well as listing every unlockable and how you get it.
It really depends on who is doing the guide. Brady Games have some very good authors, yet they also have plenty of mediocre ones.
I am hoping with the release of KHIII they will use Piggyback, because they make some of the best guides. The guide for Assassins creed 2, Metal Gear Solid 4, and both the Final Fantasy XIII games were amazing.