It was good, not great. A fast read. I was interested in most of the story lines but I wasn't transported to the middle ages. Instead, the middle ages were used as wallpaper.
The overwhelming negative, for me, was the writing. It was not fluid where I could get lost in the story. Many times I was jerked out of the story because of the sentence structure. The rhythm was off. Follet is not a wordsmith.
Again, good not great. The book could've used an editor.