This is actually a really useful book. I have used it with year 6 children as a basis for booster work and it's great. The very negative review given for this book is based on the fact that the person didn't know it was for teachers, but Amazon's product description makes this perfectly clear.
Teachers will be able to use the writing tasks as a springboard to quality discussion, ensuring that the children are clear on the features they need to include for each piece. The book also includes all the different genres which may come up in the SATS.