I love the movie that was inspired by this graphic novel, and I recently realized that although I had meant to read the book, I somehow never had. One quick library search later, I have now read and enjoyed this graphic novel.
It's impossible for me to not make comparisons between the film and the book, but in the interest of avoiding spoilers, I will say it was interesting to see which incidents in the book were repeated in the film, which were altered, and which were left out altogether. The movie has a plot, and more background information about the main characters, whereas the book is more episodic and open-ended. If you're a fan of graphic novels, you will most likely enjoy this one too. Recommended.