It's not a heady academic analysis of feminism and bisexuality, but I'm OK with that because I find those annoying. It's more of a personal memoir interspersed with thoughts about how the author has made meaning of her sex life.
I'm amusing and somewhat disturbed by some of the reviews of this book - I think they represent people's discomfort with bisexuality more than anything about the book itself. But I think that's why Baumgardner's voice is important - she challenges us to not assume anything about anyone, not not assume anyone's sexuality is fixed at any given time. I've known married "straight" women who came out in their fifties after falling in love with a woman; I've known lesbians who lived their whole lives sleeping with women before unexpectedly finding themselves in love with a man. These are uncomfortable truths for some people to hear, but that doesn't make them any more real. People want to believe sexuality and gender are rigid and exactly as we expect them, when in reality they are anything but.