This is arguably the best film version of Johnston McCulley's costumed swordfighter of old California, beating out both the 1920s Douglas Fairbanks film and the recent Banderas/Hopkins blockbuster (although both are good films in their own rights).
What this film has is Golden Age Hollywood style in spades: glamourous photography, music, and star power. It has less action than you might expect, and Tyrone Power actually spends very little time in the Zorro costume -- he's in his 'civilian' duds for the whole finale. But the film is such good-natured fun and director Mamoulian has such a solid handle on the material that it hardly matters. The romance and comedy are also well executed and finely balanced with the physical action.
Speaking of action, the big duel between Tyrone Power and Basil Rathbone is a stunner, an amazing piece of combat choreography. As a bonus, Fox Home Video has mixed the film in stereo; very rare for a film of the period. The disc also has a 45 minute episode of "Biography" about Tyrone Power. It spends only a minute on THE MARK OF ZORRO, but it does show a priceless outtake of Power dressed in the Zorro costume making fun of studio boss Darryl Zanuck. Even if you don't watch the whole documentary, make sure you speed through it to catch this riotous old Hollywood prank.