When I started reading this I thought it was another book about how to handle scope creep in product development, with yet another fictional story (sigh) to create a context.
Imagine my surprise when I realised 25% in that it really was an excellent book about Product Management, at all levels, with a lot of practical tips (and the fictional story was nearly invisible, as it should be).
I can say that this would be rated at Excellent, as it manages to convey a lot of all important aspects of Product Management, from aspiring PMs to CPMs and VPs of PM. What it is lacking is the space to explores it in more depth (but you can tell the author really knows what she is talking about when reading it). If she publishes an expanded version or another, more in-depth book, I would buy it without flinching.
All in all, I would say that this should be mandatory reading for anyone that wonders what Product Management is all about in the IT market (but it can be applied to other markets, of course).