I personally found the campaign to be lacking in many areas. I just felt that the game was to short to even possibly include the Revelations they told us about. Also, I didn't really connect with any characters. Yusuf, for example, considering he is the leader of the Assassins in Constantinople, It didn't really feel that way. Their relationship felt the same and Ezio's relationship with Leonardo. And Sofia? I had no idea that the two would get married until I saw Embers!
I guess what i'm trying to say is that I was dissapointed by the campaign. Ubisoft (in my opinion), really overhyped the game to the players. They did so to a level where I thought there was going to be a really huge revelation, in truth, there wasn't really. What do you think?