I don't really enjoy campaigns; I prefer larger maps or a good opponent. It's a shame the AI isn't the best option here... but it depends on the situation. And you don't really get to experience all the features of a particular faction in a campaign... I personally prefer playing with three castles; the others don't appeal to me as much, although in the third game, it doesn't really matter who you play as.
Here it is, different perceptions! We girls love to discuss the plot, appearance, and character of the characters, while boys are more interested in perfecting tactics and strategy.