I will be adding this to my collection. It is full of useful information, from charts, practice sentences, and cultural insight. While reading, you can see the love and appreciation the author has for the language and culture. If you look up his life, you can see he studied preww2, went on to study Japanese for the military intelligence, and aided in the Japanese occupation during ww2.
The issue I personally have is the high use of romanji. Once I learn more kanji, I will simply practice by writing in the margins. There are also a few moments where it is noticeable the different cultural norms of the time (1970s). Think “a man is most likely reading this book”.
Overall, I would recommend this book to a self learner. Highly helpful for grammar and sentence structure.