The biggest advantage to owning this book is that it is all there. It is a one stop book for referencing memory work throughout homeschooling. Anything that reduces the time I spend online looking for a poem or speech is a positive for me. Another great benefit is the broad range of selections. I particularly appreciate Dr. Campbell's inclusion of prayers from the Orthodox Church alongside prayers of the Catholic and Protestant faiths. The grammar section is nicely done, with an original catechism which when memorized takes the student through a very thorough understanding of grammar. Finally, as evidenced by the generous selection of well chosen poems, the quality of the selections is very high. There is no fluff or twaddle in this volume, only the best of the best.
Drawbacks: Those who are looking for a book divided into grade levels telling you exactly when to assign these pieces will be disappointed. However, if you are following Latin Centered Curriculum, he offers many suggestions in there for when to memorize certain pieces. If you are not planning to study any Greek or Latin, a large portion of this book will be useless. Also, the Religion section makes up a generous portion of the book. This is under the assumption that anyone following the classical model will be studying the Christian religion as a part of that, whether they are Christian or not. For those who do not wish to expose their children to christian hymns, prayers and scripture, there will be a good portion of this book that will be unusable.
It is designed to be a "workbook", or practical guide, not a theory book. If you are looking to really understand the how and why - you will want to do further reading and research. If you are looking to this book to convince you of the value of learning these things, you will be disappointed. If you are looking for a pick up and go anthology of high quality memory work, then this book is perfect.If you are interested in looking deeper into the theory and philosophy behind this book the following reading is suggested:
article on memorization
Memorize the Faith