Well folks, I finally finished this book.
It wasn't a hard read (always a good thing), although the personal stories did start getting tedious towards the end. You won't miss a whole heck of a lot by doing a little skimming. However, don't skim the final "Discussants" section. I found two of the book's best essays here. One was a sex therapist's response to the manuscript of Boston Marriages. Through sharing the book with a college class she taught, she started to re-evaluate the ways in which she assumed lesbian relationships should be treated. This is the mark of a real professional. It seems like a lot of 'experts' don't look critically at their own views; they think this close-mindedness proves their ideas' strength. In fact, I think it's quite the opposite, which is well-portrayed in this essay.
The second essay of "Discussants", "A Matter of Language", is a really lovely discussion of how quickly language fails us when we try to describe relationships that exist outside the mainstream.
The author calls Boston marriages revolutionary as an act of naming alone. If womens' rights are about women having choices, then by giving women the words to express another relationship, we just got another choice. And that is indeed a wonderful thing.