It also feels better because it is bigger. In DA2 you have Kirkwall and a few small surrounding areas. There are only about 3 different dungeons that are reused over and over again. DA scales the entire country of Ferelden and includes 2 major cities with multiple districts but also a half dozen villages and many other points of interest. You can't deny that DA is a bigger game. While that's not automatically a requirement for a better game in this case it certainly helps.