First time I saw the movie I fell asleep at some point during the Obi-Wan/Grievous grudge match. I never fall asleep during movies--theaters are too expensive to use as siesta parlors--but there was something hypnotic about the twirling colors and buzzing sounds that conveyed absolutely no information or emotion.
Still, ROTS wouldn't be my first choice for a leg surgery movie. It would be terrible to watch a Prequel knowing you can't get up and walk away.