As a person who played Rogue in both DA:O and DA2, rogue in DA2 felt much more impactful. In DA:O, I barely pushed any buttons, just placing her behind the enemy and auto-attacking. There was like one skill I would use (I think Sweeping Strike) and that was it.
In DA2, I used at least 4-5 skills, and could use them in more fun ways. Dodging an Ogre charge, by using backstab at just the right time was thrilling.