Other reviewers have already covered many of the things I admire about this book. I'd simply like to add a few other points.
The layouts are beautifully done. Having worked in publishing, I realize this never happens accidentally but is the result of careful planning and editing. The result here, which combines text, beautiful photos, blueprint-style sketches, helpful captions, pull-out quotes, sidebars, and bulleted lists, is so masterful it could serve as a textbook for graphic designers.
Sarah Susanka introduces many design concepts, such as "moving toward light" and "patterns," within the context of particular situations to show exactly how to make them work in existing spaces.
It's also obvious that her co-writer, Marc Vassallo, helped to keep the text lean yet expressive. Susanka herself confessed (in the preface to "More Not So Big Solutions for Your Home") that she has a tendency toward wordiness. That's not a problem here. Each section features a beguiling lead and then gets right to the point.
This book is a classic that I've turned to again and again whenever I need inspiration. And although we haven't moved any walls or done anything that's usually considered "remodeling," this book helped my husband and I redo several rooms -- with immensely satisfying results.