Her Fearful Symmetry

I have mentioned a couple of times now how much I love Audrey Niffenegger's The Time Traveler's Wife. When I found Her Fearful Symmetry, I figured that I would love it as well.
Her Fearful Symmetry is the story of two generations of twin girls. When Elspeth dies of cancer, she leaves her London flat to her twin sisters twin daughters, Valentina and Julia, whom she had never met. Elspeth and her twin, Edie, have not spoken in nearly 21 years, although they refused to say why.
Valentina and Julia travel to England under two conditions: they live in the flat for at least 1 year, and their parents are not allowed to enter it.
In London, they befriend their neighbors. Robert, who is was Elspeth's boyfriend, and Martin, who suffers from severe OCD. The girls struggle to establish their individuality without hurting their bond, while searching for the truth of what happened between their mother and Elspeth. However, things are soon complicated when they discover that their aunt is still haunting the flat.
I'm not entirely sure how I felt about this book. The writing was fantastic, of course, and it was a very interesting storyline. That said, I found most of the characters very unlikeable. Valentina and Julia seemed needy, co-dependent, and immature. Julia came off spoiled and selfish, and while I liked Valentina a little better, I found her rather stupid. I liked Elspeth fine until the end of the book, and then I hated her. I also thought that the story took a long time to get started. I felt like I read half the book before anything relevant happened. And I found the relationships between the girls and their neighbors to be rather far-fetched.
As much as I disliked the female characters, I liked the males. I thought that Martin was adorable. I also just felt like giving him a hug. And although Robert was less endearing, he came through for me at the end of the book. I also liked that it was unpredictable. Throughout the story, I kept trying to predict what would happen next and hardly ever guessed right. I would never have been able to predict the secret of Elspeth and Edie, and it may have been my favorite thing about the book.
Her Fearful Symmetry was darker than I imagined it would be. Although the storyline was good, there was nothing about the book that made me fall in love. I didn't fall in love with the characters, and it didn't make me cry. If anything, the ending made me angry.
I wouldn't say that I completely disliked the book, but I don't imagine I'll pass it on to my friends. But maybe it was just a little too dark and twisted for my taste.