This is a very good book on marriage, and it is particularly useful, in my opinion, for something like a small group study or pre-marital counseling. Especially strong on foundations and healthy relationship dynamics.
Two concerns for me:
1. While the headship/submission paradigm was not grounded in this, some of the language sounded awfully close to eternal functional subordination in the Trinity, and I think they could have clarified some things better in this regard.
2. The small chapters worked really well in the first two sections, but not as well in the third section on sex and physical intimacy. I think the choppy style in that section felt out of place, and it also made the topic feel dragged out a bit.
I would still recommend this for small group discussions, a marriage refresher, or premarital (with guidance). I think it could/should spark a lot of good discussions.