I feel like the book has helped me quite a bit in understanding Laozi, Zhuangzi, as well as the general ideas of Contemplative Taoism. It draws from various original writings on Taoism, as well as some more contemporary parallels. The author, Alan Watts, also uses mostly his own translations of Laozi as well as those of others. Footnotes often draw attention to differences in translations, which also is very helpful with something as widely translated as Dao De Jing.
That said, I've read the book once and am hopeful that I understand about 50%. Definitely something to re-read once or twice. This is the point that prevents me from giving it five stars, as I feel any book on Taoism should be more straightforward and not as intellectual.
For students of Chinese, the book also helpfully offers Chinese ideograms in the margins when referring to Chinese words in the main text. Moreover, the book contains a good deal of original calligraphy, used for the names of each chapter as well as quite a few quotations from Laozi, Zhuangzi, and Liezi.