Of all the versions of Zorro I've seen (that includes Douglas Fairbanks, Tyrone Power, Guy Williams, Antonio Banderas, Duncan Regehr and even George Hamilton), this one is the worst by far. It's ridiculous from beginning to end. The story barely resembles Johnston McCulley's writings (Zorro is now a Governor!), but that's a lesser problem. The main ones are ludicrous acting, terrible directing and totally trashy script.
I'll start wit the main character himself. Let's face it, in almost every version, Zorro has always been more or less effeminate in his public identity to hide his stronger secret one, but in this one that aspect is exaggerated. He is (or acts like) a true f*g who would make Liberace look as macho as John Wayne. Alain Delon is a competent actor when well directed (remember 'A Plein Soleil' or 'The Leopard'), but here he is awful and unbelievable as the sissy Governor, and only slightly better as the heroic Zorro.
The script must be witnessed to be believed: it's extremately cliched, filled with bad, unfunny jokes, and it gives an annoying dog named Assassin (which can open secret doors in houses and things like that) almost more screen time than Delon. And every time Zorro appears on screen somebody screams "Zorro!" ("thank ya, Sherlock, I hadn't realize", I almost surprised myself shouting to my TV set).
And leave the soundtrack alone. It couldn't have been more ridiculous: it consists mainly in a song that plays again and again and AGAIN during the entire movie, with a chorus that says "Laaa-la-la-laaa-la-la, Zorro is back!" Poetic, isn't it?
In summary, 2 out of 10 (it saves itself from a rating of '1' because I thought that part of the looooooooooooooooooong final fight between Zorro and the bad guy Stanley Baker was slightly entertaining. Only slightly).
Never see this movie. Go for the exciting "Mask of Zorro" instead.