There are many great things with this grammar book. There is a pop-out cheat sheet. It is pretty comprehensive. It has a ton of practice. I also like the variety of practice (not just repeating the same task over and over).
However, there are several extremely frustrating aspects of this book that made it unhelpful for me (as an advanced learner needing a quick refresher). First, the book has several mistakes. These are primarily numbering errors and formatting errors that are distracting. Second, the book is incredibly condensed and thus sacrifices clarity and explanation. Some practice sections are so limited in direction that I could not complete them. I just didn't know what was required of me. Finally, and my largest problem, is the lack of an answer key. To check my work I would need to purchase an answer key book. This is disappointing.
Some sections of this books and even some practice could be sacrificed for an answer key. I completed about 50/60 pages of this book before I realized how pointless it was. I could making and learning erroneous grammar because I don't have access to an answer key.
Ein sehr gutes Grammatikbuch der deutschen Sprache. Es wurde mir vor über 30 Jahren von meiner, übrigens sehr guten, Deutschlehrerin an der Sprachschule empfohlen und begleitet mich bis heute. Ich besitze allerdings die alte Ausgabe vom Jahr 1985😇.