The middle section dragged so much, so I actually put this book on hold for a long time. I read the first few hundred pages really quickly, but after I got into Falling Into History, I couldn't keep going. The end was really quick, so I finished it once I got through that section.
Also, I'm not sure if I felt this way after I read the Years of Rice and Salt, but the writing style is a lot more telling than anything else. There is a lot of description and not much character interaction. I'm excited to read the next one, though.