I downloaded the kindle edition in order to help me check my own writing. It is, of course, exactly what it claims to be - an accurate guide to writing style and very 'Telegraph'. Be aware that by far the largest section of the book is glossary, and that in the kindle edition there is no way to move to the required letter of the alphabet quickly; it has to be moved through laboriously one page at a time. Note to publishers: could the glossary have indexing or 'chapter' marks for each letter please? Be aware also that it goes into great detail about the correct ways to refer in print to different kinds of people. Important if you're a journalist, but less so for the general writer.
I also feel that a price of over £9 is rather high. You can get a lot of kindle-book these days for that much money.
If you want a journalist's guide to writing, this is it. If, like me, you just want a guide to help you with more general work there will be a significant part of the book you may never use.