The book is primarily a mystery, but is much more than that. William and Adso quite obviously reference Sherlock Holmes and Watson. William uses deductive reasoning to solve stuff. It also has extensive discussions about theology, the afore mentioned issue on Apostolic poverty, the different Catholic orders at the time, and the two popes. It paints a great picture of the Catholic Church, its policies, its politics and beliefs during the medieval period. It actually led me to want to learn more about that topic. As a mystery, it also works pretty wall. It is absorbing, puzzling and quite thrilling at times.
Overall, a great book which I loved and will probably join the prestigious ranks of one of my favourites. hah.