Restored version
I just saw the restored version under the Janus Films imprint, 2-28-16 at the Wexner Center for the Arts. It ran 119 minutes. I wanted to like it better than I did, being a Shakespeare fan and reading that it was one of Welles' favorites.
Pros: It makes a coherent story of Falstaff, Prince Hal, and KIng Henry IV in one work. The stark black and white photography amplifies the rough, medieval settings. The village life and recruitment scenes are convincing. The battle scenes are horrific. It leaves you with the transformation of Hal to king and Falstaff to has-been.
Cons: The dialogue from Shakespeare is rushed and mumbled so much that I mainly followed the visuals. John Gielgud is the notable exception as his voice and diction are mostly exemplary --proving that the recording is not to blame but rather the overly-wordy script and poor enunciation by the others. But, Shakespeare's lines are difficult to follow at best on stage or screen without reading the material first.
I think the style is uneven; part bawdy comedy, part over-elaborate interior scenes, part political intrigue, and the battle scene is rather too long. Don't expect the artistic cinematography and smart editing of "Citizen Kane."
Conclusion: I think you would have to be a Wellesian to love this film. For a great biographical essay on Welles by Alex Ross, see The New Yorker magazine, December 7, 2015 with many references.