Gametrailers gives 8.6/10 what is still good, but under most expectations. Anyway, what worries me the most is what they said about the dialogues:
What will propably cause you to take pause is the dialogue. Convincing as the may look, it's hard to take the characters seriously as people after hearing what they have to say. It's basically Japanese RPG melodrama, that some may find endearing though for us it's most frequently at odds with the heavy story the game is trying to tell.
Since Mass Effect I am used to ambitious dialogues. If Final Fantasy XIII is on the level of an anime for 15 year olds, that would be an argument against the game thinking of how linear it shall be and the frequent use of cut scenes. Still I think from an art style point of view, the game has fantastic visuals that makes me wanna play it.