The original film (w John Wayne) has been on TV a lot lately and I saw it for the first time about two weeks before we went to the newest film. Despite the directors' claims that the movies are very different, in fact they are remarkably similar. Whole pieces of dialog are almost verbatim (because they are lifted from the book). The characters are largely the same. I came away thinking the newer one was a simple remake of the earlier film. There are a few differences but the plot is essentially identical in both. Some random thoughts on the actors:
Jeff Bridges is slightly better than John Wayne - but only because Wayne plays against type in the movie (probably why he got an Oscar for the role). Matt Damon is, of course, better than Glen Campbell (who was a singer, not an actor). The "14 year old girl" in the story if the real star of the film and both actresses are phenomenal in their roles - easiy the best thing in either version of the film.
The new film tacks on a "many years later" scene that is from the book but missing from the older film. It may or may not add much.
Bottom line: it was a good film 45 years; it's just as good today. Better? Depends on who you ask.