I'm a little bit more than half way through and I've "flagged" so many insightful passages on my kindle because I just find this exploration of marriage so interesting. She investigates historical, sociological, cultural, psychological, etc. aspects of marriage which I find fascinating! I highly recommend it. I actually took a break from my Oscar Wao title to read this.
Overall an interesting and insightful book. A good read for anyone in a long term relationship I think, but it does become a bit dry and rambling at times in my opinion.