Why should I read the Da Vinci Code

Is it good? I heard it's like reading an novelised version of " National Treasure"

I'm actually reading the Da Vinci Code because I saw the movie, and I think that a couple of characters (namely Langdon and Silas) weren't developed enough in the movie, although they could've been really interesting.  I wanted to see if Brown had done a considerable amount more with them in the book.