If there's one thing to say about De Grauwe's book is that it seemed very useful, down to earth, in contrast to other economics books I've read. The concepts covered in the book were explained very clearly, and for someone interested in the area, the theories seemed ready for use for application in understanding the important issues of monetary integration.
Whether there are flaws in the theory are--honestly--beyond my grasp; I'd have to read more. The book seems written and revised fairly enough and hasn't received negative comments from the faculty at my university. If someone else has a contrary opinion, I'm sure it'd help for people to hear.
Check the sample pages if you want to see if this book would be good for you.