Reading this book right now and it is so good.

Was doing some half-assed internet research on the book and saw the movie with Sean Penn was universally panned as a disasaster. How on earth could they not come up with a good movie out of such a rich text?

Also, should I watch just for the entertainment factor of how terrible it is after I finish the book?

Not sure if you're aware but the Sean Penn movie wasn't the first movie made based on the book. The first one was made in the late 40's and it won the Academy Award for Best Picture.

You know how to guarantee that your movie is not going to be good? By trying to improve on a version of a movie that won best picture. It was doomed from the start.

And Broderick Crawford won Best Actor and Mercedes McCambridge won Best Supporting Actress.

It leaves out a lot that was in the book, though, unsurprisingly, and of course fails to capture the lyricism of RPW's prose.