It seems that until the 1980, when the book was printed, reality about Zen started slowly to seep in to the West, stripped of its exotic content, and the real learning about it could start. Zen is not the tea ceremony, and it is not the cherry blossom. Although, sure, it is all about having a tea with a view to the cherry blossom!
I had a great fun following Masters of various attitudes through the centuries in Hoover's writing. I knew some of the stories before, but he unearthed many more, and re-told them in a lively way. I was not bored with any of them in his rendering.
Of special value I find his exposition on the Chinese Zen. It is a mix with Taoism and Confucianism, and Hoover navigated skilfully through those murky waters of politics and philosophy.
Of the later masters in Japan, he revealed for me the magnificence of Hakuin. I was not aware of his so many achievements. He was definitely a material for the CEO, with him at the steer, Sony or Toshiba would eat Apple for the breakfast!
If you are searching for a well-balanced exposition of the Zen tradition, this is a good book. It is available from book-sellers in the printed form, and it is also freely available as e-book. I had read the freely downloaded pdf version.