Poorly placed in the series. Players at the right level for In The Beginning and Tesuji probably won't get much out of reading this book, since it basically just presents a lot of sequences players should be familiar with without in-depth explanations. As a reference, this book is clearly less complete than Ishida Yoshio's Dictionary of Basic Joseki, and doesn't add much value beyond the freely available Kogo's Joseki Dictionary.
It's not a bad read, if you are feeling lost about joseki, but it is not the best option available.