Much like Volume 1; Elegant Objects Vol 2is fantastic.
It didn't impact my mental model of how to develop software as much as Vol 1.
This Vol is more about the things that are destructive to the desired programming paradigm described in Vol 1.
It's the "CAUTION - HERE BE DRAGONS!" for what the industry uses as standard practice and patterns.
I didn't put nearly as many sticky notes into this book. The first volume got 70 sticky notes; this one got about 10.
It's a different level of information. Just as valuable to be able to be successful using the information from the first book; but hard to apply without the first book.
I describe the first book as the "How To" of writing good object oriented code. Vol 2 falls into the realm of "doing these things is bad OOP". This isn't said in a vacuum; it ties into the first book nicely. References the practices that would be violated. Vol 2 alone won't get you to be able to produce flexible/maintainable code.
Vol 2 provides some excellent examples of how to approach and resolve some situations. It actually gave me the solution for an issue I'm facing at work on how to best apply the practices for Vol 1.
There are other practices that have given name to things I already do. Some practices I did but couldn't articulate the WHY I liked them better; now I have a reason for them.
If you can only get one book; get volume 1. When you run into smells you can't quite get rid of; get volume 2. Or be like me; get them both; completely worth it.
As with the first book;
Yegor has a section on how to get a discount on the book purchase - http://www.yegor256.com/books.html#how-to-get-a-discount. I'm writing this review; I've got one amazon; and I'm not getting the discount. This book is worth every penny I've paid.
I'm more than happy to pay for material I find worth it.
Volume 1 is going to be a book I have close on hand; more so than even design patterns - volume 2 is a book I'll reference when I can't figure out how to get rid of a smell.