Much cleaner system, better turn based/live action system. Ability to chreate all of your own characters.
I didn't even find DA to be as good as Baldurs Gate II, which it was essentially copying. I felt a stronger connection to those characters than any of the canned products in DA.
To me DA didn't offer enough content to over come its terrible graphics, predictable storyline, and forced relationships.
And the sex scenes were so laughably bad that they should have just removed them. I was more convinced that the two mummies fighting in Stone Prophet were in love than when Morrigan awkwardly bumped into my creepy fingered elf. Both of them staring off into space with their dead eyes...