I've been teaching music theory for 35 years, and have seen a lot of texts that I like less than this one. However, it doesn't make this one wonderful.
As other reviewers have mentioned, there are a lot of errors. Also, there are far too many places in the examples where they say, "Ignore this note", or "Forget about this for now". You'd think they'd have found better examples without making the interested student wonder what's really going on, and the less involved student confused with excess.
This book is heavy in overkill. It's the same problem as in computer manuals: they obviously feel like they have to tell you EVERYTHING, and that nothing is more important than anything else. For example, they go on for pages and pages about chord spacing and voice leading, where a simple grounding in how to write and recognize decent melodies would go a lot farther and reduce dependance on mastering mountains of scrupulous finicky detail.
The authors obviously feel that the inner voices are no more or less important than the soprano-bass counterpoint, whereas perceptually, the soprano and bass carry most of the weight of what's heard and experienced. The emphasis is on recognizing the vertical component of harmony at the expense of the horizontal, but music is experienced as ongoing linear motion, not as successive blocks of stuff. On the other confused hand, they treat Alberti Bass as a note-to-note melodic line, where it's exprienced as just a rhythmised chord with the bass predominant. Minor scales and harmony are introduced as soon as major, and this much complexity before students know what's going on is pedagogically weak. It's the same with triads and seventh chords. And so-on.
You need to understand the simple before getting into the complex.
If you are good at taking a long string of finicky detail where all is of equal importance, and developing it all into a bigger picture with hierarchies, this book might be good for you. Otherwise, keep looking.