I am going to say that it is a mixture of both.
I actually saw the new film adaptation with Daniel Craig before I read the book. I thought the movie was pretty good and was expecting the book to be better.
What I found, was that the book moved smoothly and kept my attention. I would have liked a little more action, like the movie, but I still enjoyed the overall plot and the idea of this mystery 'murder'.
I am not going to say this is the best book I have ever read, and that you absolutely have to read it. But, if you want to try something a little different, give it a shot.
3 out of 5 stars, I liked it