Yeah it really adds to the immersion and clarity of who you are talking to. And make the titles fluid! If you are a vassal but own no fiefs maybe you get no title, if you own a village you are a baron, a castle a count, a town a duke, and then the faction leader is the king/emperor/whatever. And then let the titles change based on the tides of war! This would also be helpful for the women in the game since some of them are fief owners and some aren't, adding countess/duchess or something to seperate them from "lady whoever" would be cool.