This is honestly one of the best Peggy Sue Fics I've read. What is notable is that the author makes a cohesive attempt to treat the Uchiha clan in a way that doesn't follow the usually tendencies, where everyone and their Uncle hates the village. The storyline of the attempted coup is developed alongside Itachi's time-travelling adventures, and you find yourself sympathizing with the Uchiha clan, as well as sympathizing with both Itachis.
Itachi's interactions with himself are sometimes hilarious, the younger referring to the older as "The Other" and the older one referring to the younger as "kitten", because his mental attacks are about as effective as the batting of a kitten's paw. Their interactions also lead you to wondering at differing viewpoints of it all, especially the older Itachi's extremely jaded, cynical, and pained view; there are many points at which the younger Itachi has to remind himself that he doesn't have the older one's sickness, because the phantom pains are so real, and convince himself that he isn't going insane the way he thinks he is. Also rather heart-wrenching are Sasuke and Shisui's worrying over Itachi, the two being the only ones that really notice when it's "nii-san" and when it's the other person that they don't recognize.
Note: as in most stories, Danzo is manipulative and evil. So is Tobi/Madara. And Itachi's ANBU team is rather mean.
The story also ties up the loose ends well enough, my only question being: What happened to the Kisame that was living in Itachi's head in the last few chapters?