Sao has two arcs
The first arc is awesome cuz its an episodic Slice of life with action scenes. Think of Mushishi trying to be a shounen with a 10 years old being the main charater. Score:9/10
The second arc is the clichéd good old story from the 80-90's where the girl gets catched by a pervert old man and our hero has to rescue her. But it has incest, hentai tentacles, and a harem. There are no words to describe it. Score: 10/10
9+10/2=9.5 (10) masterpiece XD