I've heard some people disagree, but despite the density I really liked this book. The dialogue could have been better but I really felt for the characters and wanted them to be OK. I couldn't put it down, despite the fact that it took up a better part of my vacation week to read it. I'm glad that PB recommended it to me.
Overall plot revolves around the building of a cathedral and two generations of families (and monks) who are involved in that building. The attention to detail and the amount of research that must have gone into this is astonishing. Overall, I give it a B+.