I didn't use the first edition of the guide as much as I thought I would when it first came out oh so many years ago. But when the new 2nd edition was released I was interested to see what changes they had made. I was very surprised to find it so useful. There is a lot of great descriptions for the different architectures possible with the .NET framework. I found this to be a great refrence for documenting architectures for the projects I work on. It helped me organize my thoughts, and consider items to include (and to leave out) of my architecture documentation. One thing I noticed was the printed version is different than the PDF available for download from the CodePlex web site. Not sure why they are different, but I found the print version a bit better to follow.