The Textbook. It's like a teacher, but in book form

When I first started to think about textbooks, I tried to think of how they appeal to students and teachers. I immediately compared my Musicianship book to my Italian Diction for Singers book. The too seem to be polar opposites in their look and the approach to teaching. However, the core of what they are trying to teach, meaning training the ear, is the same.
The Musician's Guide to Aural Skills Volume I is a very fat, soft, and hearty textbook. It's pages can be folded over making it a perfect for highlighting and marking measures and measures of sight-singing. It also has a nice background of theory presented at the beginning of each chapter so the reader knows the purpose of each exercise. It is good for both use inside and outside of class. The explanations and rules on the inside are not written in lengthy prose. Rather, they are written in short, poignant sentences that are precisely to the point. Basically, it screams "Hey! I'm a textbook! I'm not something you really want to pick up for leisure reading."
Singers' Italian: A Manual of Diction and Phonetics takes a slightly different approach. It is a small, very compact, one hundred and fifty page book, that resembles a novel or a casual reading book. the pages are filled with tiny letters, so it is not very easy to write in or highlight. It is set up in chapters. Each chapter begins with a rule, and then the author, Colorni, gives examples, exceptions to the rules, and plenty of practice for the reader. The only thing this book lacks is a great explanation of the technique of making certain sounds. Colorni uses a lengthier style of writing, which is very different from the direct Musicianship book. The strategy of this style of textbook seems to be an appeal to those who do not want to read a textbook. This book seems to have more "coffee table" appeal, if you will.
I do not have a preference when it comes to my learning style. I can learn from either style, but I found it interesting to compare the two.