Demanding but rewarding. It is meant to be used after Noboku & Osamu Mizutani's 'An Introduction to Modern Japanese', another good prereq is Eleanor H. Jorden's 'Beginning Japanese 1 & 2' and 'Reading Japanese'.
As a self-learner this book was awesome, you can do all of the exercises by yourself, there are no audio and classroom exercises.
The grammar exercises in the book are in the same style as in Noboku & Osamu Mizutani's first book: you get formulaic dialogues where you replace words and expressions with alternatives. However in this book the authors encourage you to go beyond the formulaic expressions and give you examples of how you can make good alternatives. It has a very large number of drill exercises.
What struck me the most with the book was the sheer amount of reading material and vocabulary. You get a main text, dialogues, and a Kanji-compound reading text. In each lesson you get about 80 new vocabulary and 100 Kanji-compund words.
It has black & white photos and the readings cover Japanese culture & society.
I was a big fan of Noboku & Osamu Mizutani's 'An Introduction to Modern Japanese', it was the very first book I used to learn Japanese, so for me it was only natural to continue with this sequel. I really liked it.