"The TKT Course" is the first book I have read on the Teacher Knowledge Test, and I have to admit that I liked the format and the simplicity of the book. There are a few reasons for this.
Firstly, each unit follows the same format and has "Key Teaching Concepts" as well as reflection sections, self-discovery tasks and follow-up tasks. These tasks relate to the unit in which they are found, and add some extra dimensions to the information there. Although one could accuse the book of being formulaic, the formula seems to work.
Each unit has a TKT practice part, which relates directly to the type of questions that will be encountered in the TKT itself. These are also supplemented by end-of-module practice tests, again related to the TKT itself. The entire book is organised into modules that match the modules of the TKT itself.
Finally, key vocabulary is all highlighted in bold in order to get the reader's attention. Reading this book has been a useful refresher for my own awareness of teaching vocabulary, so there has also been a benefit there.
In short, although the book is not long, it is an information packed resource that will help people prepare for the TKT well. However, even besides the TKT, there is a lot of good information in there. The book primarily focuses on 3 techniques: PPP, TBL and TTT. It is a good resource and is very easy to read and get into without huge amounts of linguistic jargon.