I lost my first copy of this book and liked it enough to get another, so I guess I must think it's pretty good. The main topic is the robotic task of Simultaneous Localization and Mapping (SLAM) and all of the (various) subproblems therein. I find it does a very good job of explaining the basic approaches and their building blocks (e.g. Kalman filters, particle filters) and gives a good foundation for reading more recent work.
Great book, with clear and full mathematical explanations of complex topics. It is still recommended after 17 years of publishing. Although some topics are a bit outdated, most are fundamental stuff that will outlive the authors.
Really quite excellent textbook on a challenging topic. Author does a wonderful job presenting challenging material in a (relatively) easy-to-consume manner.