The pacing of the campaign map is much slower, so you can actually build a connection with your characters rather than having them die out way too quickly. In regards to vanilla campaign, I would say that TW: Attila is better. I've always wanted to do that!), though TW:R2 has a lot more campaign options to go with, assuming you are buying the dlc. TW: Attila does have some very interesting game mechanics (I could set the world on fire.
