Maybe I am in the minority here, but I thought the visuals and music were mostly okay to fine in episode III despite some over the top sillyness.
But the script was pure awful and so was the execution in directing the actors for all three prequel films. But Episodes II and III were far worse at least episode 1 focused somewhat on character development and was shot on film and had real models along with the painfully out of place in star wars cgi and cartoon characters not at all in step with the mentality of the oot.
The editing was Crap the cinematography was nothing to write home about the effects looked cheap not in cost but in being a cheat.
The music unmemorable except for Anakin's Theme in Episode 1, Duel of the Fates, Across the stars and battle of the heroes.
If Jedi was a step down from star wars and empire in quality the prequels are are mere shadow of even the worst moments of jedi.
The swashbuckling adventure Lucas somewhat hinted at bringing back in Episodes II and III was nowhere to be found. Instead you got a 4 hour video game that was non interactive, and were bored to tears by the politics, and there were no likeable characters i hated the jedi and sith and republic and empire and seperatists they all came of as false and not real characters.