This book was fairly well structured and easy to read, although my interest waned during about half of it, because those parts were simply less relevant to me (about half the time he speaks to married people, a fourth of the time to singles, and a fourth of the time to adulterers, and only the first is applicable to me). I found most of his advice on sex truthful and appropriate (which is only to say I agreed with him most of the time), and I found his cultural analysis of how our society treats sex (and why that's a bad thing) to be insightful (which, once again, is only to say I agreed with him most of the time).
One thing that somewhat bothered me about this book was the way he occasionally used it as a vehicle to critique Christianity. I wouldn't have a problem if he had written an entire, separate book about "What's Wrong With Christian Philosophy," but the way his critique was piggybacked onto a book about sex and interspersed throughout, sometimes very subtly (so that Christianity was not even directly mentioned, but a serious Christian would recognize the target), seemed slightly disingenuous to me. I do think this would be an interesting separate book, if he was being direct about his critique, and one I would definitely be interested in reading and contemplating. I think such a book would be a good book for Christians to read, because I think we have much to learn from Judaism. Historically, Christianity has been very strongly influenced by non-biblical philosophies, and Christians may actually gain a clearer understanding of Christ's teachings in light of Judaism. However, I did feel as though Rabbi Boteach misunderstood Christianity somewhat. Oddly enough, despite his critiques, his view of sex almost perfectly mirrors that of an Evangelical Protestant or a devout Catholic, though he sees it as being a more positive view (as being more good-and-practicality focused vs. the Christian view, which he perceives as being be more negatively sin-and-morality focused).
Overall, Kosher Sex is a pretty good book, but more as a social commentary than as a book of practical marriage advice. He does lean heavily on the anecdotes, and he does repeat a few statistical canards. For instance, he throws out the much misused and misunderstood 50% divorce rate, taking it even farther to say that "50% of the population" is divorced, when, in reality, it's about 10% of the population that is divorced, and of those who have ever been married, only 35% have ever been divorced.