The way I see it, Yaya is an awesome option for City as he gives us something extra with his size and build alongside our midgets. Crucially however, he has the touch and technique to keep up with the others in fast one-touch play.
IMO, if we are going to go for a target man, we need one who will be a forward equivalent of Yaya. The only one I can think of in world football is Zlatan...or to a lesser extent Balo if he gets his shit together.
Whatever happens in the summer, I don't want to see Cavani or Llorente coming in, good as they are.