I'm teaching a Chinese class to a group of American kids with almost no other exposure to Chinses out of my classroom. I choose this book for my class because it's the only one I have found that's oriented to kids. and the contents much covers many of the essential topics that would be covered for beginners.
Maybe I'm picky, but the audio can use some improvement. For one thing, if all possible, it's better to use native English speakers to pronounce the English portion. The idea of using kid's voice is neat, however, their accent (very light though) does have a slight negative impact.
I don't like the idea of teaching Pinyin right away, which in this book is the first unit. also the part about family members should have its own spot as one lesson, instead of just being there as reference.
bottom line, if you have a teacher that you see regularly, this book is useful; if you want to teach yourself, look elsewhere. However, I must say that one is not going very far without a teacher.