While I believe that DA:O was the better game, there were some things that DA2 did that I preferred (and I liked both games A LOT).
DA2 Improvements:
-Talking protagonist with a name. No more awkward "the Grey Warden" or "the Hero of Ferelden" dialogue dances. Hawke looked and felt more like a person, which I think helped the story (actual story is another matter...).
-Lack of "Put 4 Ranks in Persuasion to WIN at Dialogue". DA:O had a gaping flaw in its storytelling sections. Whenever a dialogue option showed up with a (Persuade) tag next to it, you knew it was THE BEST option. There was never a chance of persuading someone wrongly. The lack of "win" in dialogue made it murkier and more believable (especially when the story was supposed to be murky and Hawke unsure).
-Combat. I <3 some 3.5 turn based actions, but DA2 had a more flowing, responsive combat system. Plus, class combos, although unwieldy, let everyone get in on what had been a Mage-only metagame in the first DA.
-Art Design. DA2 had a unified art design to its world, it's characters, and its gear. There should have been MORE, but it looked unique, and wasn't just "generic D&D fantasy world" in its stylistic choices.
-Varric. And Bianca.
And to beat a dead horse, here's the biggest things I think DA:O did better:
-Story. My God, the story. The sad part is, I think Hawke's story had the POTENTIAL to be the far superior. Origins was a very classic "unite the realm to fend off evil" D&D campaign. Great fun, well executed, and a throwback to nights in the basement, but it wasn't anything really "wow" inducing. DA2's story of a rise-to-power, the costs and choices that built that rise, and the rubble of those who were climbed over... that had a lot of drama potential. Unfortunately, the three-act structure felt broken. The underlying malaise of Kirkwall's fade problem never really rose to a boil (and it should have!), Flemeth was a red herring lead to another storyline (same with the fricking mirror), and the second act climax felt much more like the game-changing conclusion to the characters' stories than the actual third act, which just kind of happened. With more time to build upon the flaws in Kirkwall's very nature, the encroaching corruption in the fade, the mirrors, and in lyrium itself, the growing pressure of madness inside the city... there could have been a truly EPIC end to the campaign. Instead, the third act fizzled hard and failed to unite the disparate plot threads of the first and second acts. (Wow, that was a small essay!)
-Companions. I don't mean quality of writing here, I mean quantity. There simply wasn't enough dialogue and interplay with the party members in DA2. I love all the companions, but there was a lot of ME2-style "Sorry, I'm calibrating" going on, which speaks of lack of time. Also, let me gear them. Srsly.
-Reused dungeons and a tiny world. Really? Did you think no one would notice? We're playing an RPG here. We're already obsessive-compulsive nerds. We're going to notice.
So, yeah. Go ahead and bring over some of the ideas from DA2, but do them with the polish and scope of DA:O, and I think there's a great game to be had!
