This is the second WPF book I read after, Pro WPF. It's shorter than Pro WPF (620 pages versus 931 pages) and it does not have the extensive index of Pro WPF. But I find it is the WPF book I refer to for examples. And it's the book with several bookmarks sticking out of it, which means it's the one I've been using. Since it was not the first WPF book I read, on my first reading, I mostly skimmed the content, looking for new stuff. Since then, I've returned to read several chapters as review.
One noticeable feature of this book is that it is printed in full color, which in case you somehow manage to miss it, is proclaimed in large type on the cover. And for some reason, the fact that "Code samples appear as the do in Visual Studio!" is also displayed on the cover. Of course, the code samples in the book do not match my Visual Studio, since I'm not using the default colors. The color is helpful in some circumstances, such as when displaying color gradients. And I like the color in the code. But when I first opened the book, I was actually put off by the color choices, particularly for the Tip and Warning sections, which make things a little too busy in combination with everything else.
Color aside, there are some excellent illustrations that succinctly show important WPF concepts, such as Figure 5.1 on page 128 which visually describes the vertical and horizontal alignment, margin and padding properties.
I also enjoyed the Warning, Digging Deeper, and Tip sections that contain useful information that does not fit in the natural narrative (although I found myself searching for some of these because the content wasn't indexed). I also found the order of material presented in this book to be better than Pro WPF, which seemed somewhat out of order. As compared to Pro WPF, this is probably the better introductory book and may not be as well suited for in depth reference. At my current level of experience with WPF, it's the book I open up if I want a quick reminder on how a simple things work in WPF.