I read this book for my book club. For writing, I'd rate it 5 stars. The description is so vivid, my mind was as full of images as it was words. The dialogue is wonderful too, especially that of Boris. He lit up every scene he was in. And the weaving together of complex plot and thematic elements was so brilliant it seemed effortless, which of course it was not. 
 On the other hand, it dragged on at times, and I'd find my mind wandering, wondering when I'd get to a 'good part' again. So for keeping me engaged, I'd give it 3 stars. Thus, my final rating of 4 stars. 
 Definitely worth the read if you go into knowing it will take you a while to get through. Lots of dense passages and lots of pages.