There are definitely two sides to this book.
Neil Degrasse Tyson takes the scientific debate about Pluto's planetary status seriously and there is lots of real astronomy in this book. However, he is also an entertaining writer and catches the emotional attachment to Pluto as a planet that made its downgrading such a big deal, especially for children. He succeeds in bring the serious and fun elements together.
This book is an informative and accessible history of Pluto and of the changes in our knowledge of the solar system that have lead to a revisiting of our understanding of our little corner of the galaxy. There is enough of the detail to appreciate the real science, and to see the personalities involved in the debate about how to describe the findings to a wider audience.
He wants us to appreciate Pluto and its surroundings for what they are, and not just to learn a list of planets.
The emotional side of the debate makes the book stand out. This is a very human issue, and, through his role in the New York's American Museum of Natural History he became identified as the man who killed Pluto. The discoverer of Pluto had always defend his historic planet-finding moment. Thousands of school-children wrote in to protest at the potential downgrading of Pluto to dwarf planet. Their letters are scattered throughout the book and are great fun. Newspaper cartoonists had a great time with the topic too, and a great selection is included.
Over this book is a treasure-trove of good science and fun things, and well worth a read.