This book was recommended by a colleague of my husband's at work, and he wanted it for our wedding anniversary. He is about one-eighth of his way into it, and says it is heavy going. It appears that he has given up on it! I had a quick look, but put it down as it seems difficult to read. More academic really than readable.
I finished this book in 36 hours. It is gripping, but written for a short attention span as the chapters are very short. It was very easy to read and covered some interesting details about the Freemasons and mathematical/symbol codes. Dan Brown is a very clever author. It is set in Washington DC, and having been there I was able to identify with the buildings.