I bought this book several months ago and I can attest to how good it is. Along with Working Effectively with Legacy Code by Michael Feathers it has been a great reference tool for working with the projects I have had.
It hasn’t been directly applicable to the code I have had to deal with which has been old Code Igniter projects where the developers had no idea what MVC or DRY or any best practices are. But the ideas behind the steps and methods to pull logic from the madness has helped immensely.
Personally, the best thought I’ve taken away is to not take on a monolith monolithically. Work at chipping away at it and not a full rewrite from scratch.