Don't buy this book; it would be a two-fold waste of your money. But I did, so read on -in order to avoid making my mistake an useless one.
First, the technical aspects: this file stinks. Seriously, it's not even worth a tenth of its price and size; it's -very- poorly scanned from the original book, with no colors, text search or bookmarks. You can see small scratches and cuts on the paper, images and text have the roughest edges ever, and it's all blurred. The file itself is HUGE -86 Megs, and that's what you get for making a PDF file out of 250+ images instead of true Acrobat pages. To make a long story short, this is probably the WORST PDF I've ever saw.
Now, about the book itself: I found it largely useless. It doesn't add much to Apocalypse. Glass Walkers are now called Wardens of Man, and that's the only difference I've noticed so far