I read this lovely novel on the plane home from Japan, finishing it upon my return to the US. I was surprised - given that it was written by a Western man - how accurately the Japanese culture was portrayed (at least from the limited knowledge I gleaned during my short time living there, and given that it was set in a time when Japan was, in many ways, very different from today).
Perhaps it was because I'd just left this beautiful country, but I was clearly able to imagine the vivid depictions described by Chiyo/Sayuri. When I was in Kyoto, my friends and I were lucky enough to see a maiko-san walking back to her okiya (a relatively rare event these days), and I will forever associate my memory of that elegant young girl with this book.
All of that said, if the author did violate a confidentiality agreement with his primary source, it is abhorrent that he did so. He allegedly also embellished the truth of certain aspects of life as a geisha, which is disappointing; and yet many authors take artistic license. Whether 100% accurate or not, the story is poetic as a work of fiction.