A few friends had mentioned this book and it piqued my interest as possibly being a bit more modern on Sunday school. Plus it's written by a man and a woman who collaborate and aren't married, which is practically unheard of in LDS culture.
It's standard Sunday school fare with some interesting thoughts, stories, and context on scriptural phrases found throughout the D&C. Both authors have experience in CEC callings/jobs and so it doesn't feel much different from a seminary or institute class devotional thought.
I did feel like a lot of the entries were very tangential to the actual text. Each entry starts with an except from the scriptural section that will be highlighted in the devotional entry. Sometimes it was a verse, with key phrases bolded, but way too often it was the phrase all on its own, without even a complete sentence around it. While this book is meant to be a companion to scripture study and you can easily find the full context in the scripture, I felt that this practice lent to many of the entries wandering far from the text itself, and sometimes the removal from context led to misinterpretation (section 89 has such an overgeneralization).
For readers who are looking for something that might help them boost their personal study, especially in interest or frequency, I think the book can be a useful tool, and many will enjoy it. For people looking for something more nuanced than Sunday school, this book isn't it.