It wasn't the lightsaber duels that caused me concern for my son -- it was seeing the dead Jedi younglings strewn about, and more so, the crispy Anakin scenes. I think PG-13 was appropriate.
Precisely. I also think I would have a hard time explaining why this happened to Anakin to my five year old. Dooku, the bad guy is one thing. Anakin, the central character to the story, and the graphic imagery is another.