This is a great movie, and if I was reviewing the original, I'd give it 5 stars. I found out about this version after I read Rob Lowe's "Stories I Only Tell My Friends", which I highly recommend. His book gives a very detailed behind-the-scenes look at the making of The Outsiders, and references many of the scenes that were cut from the original. For the most part, the additional scenes are welcome additions, and do a nice job of filling in some of the things that were puzzling or unclear in the original, like why does Pony Boy have a cut on his neck at the beginning of the movie. They also add a lot of depth to the relationship between the three brothers, especially Pony Boy and Soda Pop. I think anyone who has a brother could relate to this. The rating loses a star because of the strange music additions to this addition. In the original, the music was subdued, like in the first scenes when Pony, Johnny and Dallas are on their way to the drive in, with "Gloria" playing as background. It doesn't interfere with the action, but adds a gritty feeling underneath. There are many musical additions that range from distracting ("Wipeout" type guitar riffs during the rumble and church fire) to laughable (an Elvis song about trains during the train escape scenes, and a song with the lyrics "cut my hair" during the, you guessed it, scene when they cut their hair at the church). The added music is way too loud-- I don't know what, if anything, Coppola had to do with this edition, but I find it hard to believe that he or anyone else was paying attention to the sound mix. Maybe Coppola had always been jealous of the songs George Lucas used in American Graffiti, because they are all played at full volume in this version, just like in American Graffiti. They work in Lucas's movie because there is more movement and action. They destroy the drama in The Outsiders: The Complete Novel.
I don't remember reading the book, but I went to high school in the USA, so I must have read it at some point. I understand that the additional scenes make the movie more true to the book, so if you're a book reader, this might be the better version for you, but if you have never seen or read The Outsiders, watch the original movie first and come back to this later- think of it as a DVD special feature.
I should also mention that it is great to see all of the actors who went on to greatness after appearing in this movie. They are still learning their craft in a lot of scenes, but there's some real emotion and greatness there too.