I finally finished it! I am excited because it was starting to drag on a bit. It is loaded with some great concepts, and the layout makes for fast page turning, but the structure and style just got a bit tedious after a while.
Dan Roam has a solid premise and backs it up with a complete set of tools. He first proves how everyone is visual and then explains the steps in visualizing (look, see, think, show). He walks you through each step, with clear examples. Then he goes on to explain how your mind works along the lines of the questions who, what, when, where and why and maps a specific type of diagram to each question. In this way he shows you how to do research and take what you see and show it in a cogent way. This book is really a useful tool.
What I found detracting was how it was difficult to read as a normal book. There were, obviously, a lot of images. He drew examples for every chart and every idea. Each example was captioned so well you could literally flip through the book like a slide show. This method of thoroughness seems like a great idea but it ended making a lot of the body copy extraneous. This was only exacerbated by the fact that he liked to restate his point. Admittedly, this is usually a good idea but in this case it didn’t work.
I’d definitely recommend the book. However, if I were to do it again, I’d skip to the back to his 10.5 Commandments of Visual Thinking and then just go review the interesting sections.