OK, it's not the best western ever produced. It's more of a full color film in the style of the old Republic westerns of the 30s and 40s. What it does have is a pretty fast moving story line, scene stealing character actors, and very pretty music (except for Jack Elam's mouth harp...).
John Wayne is moving from leading man with love interest to lovable old coot. Jorge Rivera takes over as the hunk. This is early in his acting career and very early in his English, but he's a doll to look at and OBTW, he does an outstanding leap over a fence. Christopher Mitchum looks very much like his father, and the chemistry between him and Wayne is similar to that of his father and Wayne (see Bob in El Dorado and Chris later in Big Jake).
This was Jennifer O'Neal's first movie, and it shows. But Wayne was famous for introducing new actors, even when it was clear they needed practice. Must have been because of the way Wayne himself was mentored in the 30s by John Ford, et. al. Watch his early work and see his own improvement.
Sherry Lansing was sexy and later vengeful. In the latter role, she, too, chewed up the scenery. She could have had a respectable acting career, but chose to shatter the movie mogul glass ceiling instead, and more power to her.
Then there's the scene stealers. David Huddleston can steal one just by being in it. Victor French is both scary and a coward simultaneously, a hard combination, but he can certainly pull it off. Hank Worden only had one scene, but he's as neat as ever. And finally, Jack Elam was a scenery chewing, crazy eyed loonie, with some of the funniest lines in the whole movie.
No, it's not the best, but I like it. It will always be in my personal movie stash.