I think he's overrated in that the man was uncomfortable handling action scenes and had to leave these to other directors like Margheriti, Giancarlo Santi and de Martino. The scenes with his protagonists and antagonists standing about for what seems like an eternity before a duel would be nothing without Morricone's music accompanying them. Don't misunderstand, I like his movies and ONCE UPON A TIME IN THE WEST is one of my favorite films of all time, but SSOOOOO much praise and near Godhood is heaped on the man as if he was the be all and end all of SWs. He was a great director but he wasn't the ONLY great director of SWs and he certainly was not without faults as none of the others were either.
Even though he directed only 7 movies, none of them were really different from the others. He never showed versatility as Corbucci did but then, he took so long to do one film, and maybe he never cared to stray from his "formula". Plus his attitude concerning MY NAME IS NOBODY put me off to him a bit as well.
The one thing I will say about his films that I can't really say for the others, is that you wouldn't necessarily have to know what the characters were saying in his movies. They're like pictures that tell the story without words. Even though the duel scenes would have little to no impact without Morricone's superb music, the scenes tell you all you need to know.