The movie plots are very similar. There are some differences but I will address them later. The plot of Nick the upstart broker coming to Long Island for the summer is the same. His reuniting with cousin Daisy and her husband Tom Buchanan for Lunch with friend Jordan, and the discussion of the place of the white race in society is the same. New York City adventures and the fun with Tom's mistress Myrtle and her sister also takes place in both. The parties, the longing for Daisy by Gatsby, and the tragedy is also similar.
The main difference is that in the 2013 version Nick opens the movie talking with a Doctor at a Sanitarium. Nick has a breakdown of sorts in Baz Luhrman's film.
The truth of the matter is the approach of the director of the 2013 version gives a darker side to the story that I find inappropriate to the storyline. He uses the film in a way that gives one the feeling of watching a 1920's era movie. The 1920's were a time of gaiety and fun. The signs of what was coming was not yet know. In the 1974 version the viewer sees the 1920's as a time of happiness and joy. The remake distorts that feeling. It tries to show the seedier side of the times, which is fine, but in my interpretation of the book there was laughter and joy rather than darkness.
My biggest complaint: Leonardo DiCaprio as Gatsby. Gatsby is a gangster of sort who has to deal with a lower form of human element and I just find his boyish looks to be to child like for the role . He is a good actor but his look doesn't fit the part. Robert Redford carried the look and feel of Gatsby very well in the 1974 movie. He is able to fit in both worlds. Redford played the character of good guy in the bad guy world role for many of his films. The kid just doesn't pull it off. I also found the other actors of the 1974 film to fit their roles very well.
Now if I was to choose between the two, I would have to say I prefer The Great Gatsby 1974 over the 2013 version. This is not to say that you should not go see the 2013 film. You choose. For some of you who are around 20-30 years old I'm sure you would choose the 2013 version over the 1974. I being of the age that I am choose the 1974 film and wish you Happy Choices. Enjoy.