I find the title to be misleading and contrary to what it suggests it is not about PMs having to manage several projects and how to do it.
It is more about a manager of a team dealing with several projects. There are some notions of leading a group/team, but one over which you (as manager) have authority, and as such not that much applicable to PMs who manage transversal, virtual teams.
The contents is a bit too lengthy compared to what’s actually being said. The book could easily be reduced in half. This being said, if you are a new and inexperienced PMO team leader, this book would certainly prove of value to you.