If you come across it at a price you feel comfortable paying, get it. But getting it is not necessarily a priority. I've seen it several times and opted not to purchase it simply because it covers pretty much the same material other books cover.
You know, it's like the Jimmy Dorsey book for saxophonists and a lot of other books. While some of the text may be unique and while it might have its own slant, usually they all head towards the same goals. Good or fun to have but not a priority.