This first book of Towles was absolutely well worth reading. It just doesn't match up to his second book (which I read first).
His second book - A Gentleman in Moscow - has the distinction of having been loved by every single person in my book club, a feat that has never been beaten in our 10-year history. So, there was no way I was going into this book without a zillion expectations. The good news is that his writing craft is still second to none, and he still knows how to build a slow-burn story.
Our heroine seems to meander through most of the book, rather aimlessly, it would seem to the reader. All is for a purpose, though, and nothing isn't interesting. It's perfectly okay that at times you wonder why so many random characters keep popping up - how could they possibly all matter in the end? - and this is likely my main criticism of the novel, that it's damn hard to keep track of all these people! I double dog dare you to figure out who she married on your first guess.
However, the book had a very powerful ending, an excellent rumination on the impact of our young adult years on who we grow up to be, and how it matters far far longer than we think it does. I recommend it for that reason, but it doesn't need to be the sole reason. He's such a damn good writer; I would read literally anything he wrote.