I am a full-time IELTS teacher and have been using this book since it was published in my class on the Gold Coast in Queensland. This is a great book for practicing all aspects of the test in a real situation. In my class we use it on a regular basis.
I find the best way to use it is to first study a reliable text like "Foundation IELTS Masterclass", and then find a task from this text that can be used to reinforce the text. For example, if we study how to write a process essay in the class, I search for a process essay in one of the Cambridge IELTS books.
Cambridge IELTS 13 has the following writing task 1 question types:
Test 1: Maps Test 2: Column graph Test 3: Bar chart Test 4: Plans
A very good and actual book to test and train your English skills. It's one of the most recent versions of this collection and the information provided is accurate and ideal to prepare you for the IELTS Academic exam.