I have finished the book now, and I really enjoyed it. I thought that it was very engaging, and I felt emotionally invested in the characters. The characters weren't flawless and had varying appeal, but I could empathize with their decisions. I found the history very interesting. I had never heard of Biafra and and was completely ignorant of Nigerian history, other than a shallow understanding of the typical issues seen when colonies gain independence. I expected the issues to be mostly tribal and did not expect the religious separation between North and South.
My minor complaint is that the story at times was too neatly tied together. It seemed that she had a long list of the various aspects of history that she wanted to represent and then made characters for each of these items. I just wondered how much of the people would have seen that great a cross-section of the issues happening to their direct friends and family.