I wouldn't say this was a bad book, but you'd have to be a newbie to downsizing a house to find it terribly useful. Having participated in cleaning out my parents' home after they died, much of this was old hat to me. If it's your first time dealing with an entire house, though, you would probably find this book helpful. While this book encourages you to think of the feelings of all involved in the process and be gentle with your emotions, there isn't much info on dealing with those emotions. In the same vein, the book suggest you ask yourself if you're keeping certain items simply because they belonged to a parent; unfortunately, if the answer to that question is yes, there are no suggestions on how to let go while preserving the memories.
There are some very handy and comprehensive lists of resources in this book: how to find appraisers, what is involved in an estate sale, ways to sell items from yard sales to online auctions, etc. I imagine a number of readers will find those very helpful.