A little on the fence about this one. Some of the essays were fairly interesting, and the matter in general resonates with me anyway. However, I found the whole too similalr in terms of backgrounds (white, middle-class, not much variety here), and too often, when reading between the lines, most of the writers involved were of the 'I didn't have kids/didn't think about it when I had the chance, and now I'm glad of it'—not exactly 'I made a conscious decision not to have any children when I was 20' or 'I've always known I didn't want any.'
Although this may make me look shallow or callous, I don't care. I do relate much more to the few who openly made that very decision or at least 'knew'. I am the same kind of person who will start a relationship by immediately bringing the matter of 'just so that you know, I don't want kids and I won't change my mind'—because, let's face it, I'm nearing 40 and I'm not going to waste my time (nor my prospective partner's) with building a relationship based on the false assumption/delusion that 'they'll change their minds.' To quote Tim Kreider's essay in the book, 'people have a bottomless capacity to delude themselves that their partners will eventually change' (in other words: never assume they will).
So: interesting, but could've done with more diversity.
Hm. I should probably write an essay of my own about that someday. Never tried it, but it'd be an interesting exercise at the very least.