I'm a fan. I like all his books, and especially how he changes settings and genres between the books. This starts as a past/present book, but the present becomes more and more past as the story continue. As in, the story starts in 20-- and in the end 'the present' is in the 1920s. And, this is one of the few books in which I like both stories.
I didn't really know anything about the Romanovs, except that they were killed and some people still claim to be one of the princesses. This book filled me in with more details, which I always like. The ending was a bit unrealistic, but it didn't really matter for me.
Note: I read a Dutch translation of this book.