While trolling the e-reviews on Amazon.com, I noticed that opinion on Memoirs seems to be equally divided between people who think it has a fairly lame excuse for a plot - and people who think, to heck with the plot, the details of geisha life are worth the price of admission alone.
(And one fascinating reviewer who pointed out that this type of story - poor-girl-makes-good-and-wins-love - is actually a fairly common plot for romance novels in Japan; it's only in the West we consider it high literature.)

Me, I think it's a remarkable technical triumph, if nothing else, for an American male author.