I bought this the morning after DDay. My husband read it in a couple hours - it's a short book but is really spot-on. I read it too and felt it really showed my experience well.
My husband's communication changed 180 degrees after reading this book. He started talking. He'd been apologetic since almost the very beginning, but now he started communicating and realizing the depth of what he'd done. He read the book a 2nd time the same weekend, then 2 more times over the week. I think it helped lead to his crisis-click moment where all his defenses finally fell away and the staggered truths just became a waterfall of them.
We are now reading NOT Just friends, which was a really good book to follow-up this one to. This one helps get things rolling and understand the emotional side, and NOT Just friends seems to be more about helping understand the whys and what to dos now