Personally, I think anybody who says DAO's soundtrack was better is doing so purely out of nostalgia. When I heard the Ostagar theme playing when I met up with some Grey Wardens (at the climax of act 2) I almost teared up from the overwhelming nostalgia. I don't know about 'half' of the soundtrack being from DAO, but I can only recall hearing the aforementioned Ostagar theme, the Dwarf theme, and the Lake Calenhad theme (which frankly I think was put to better use here, in an area that was frequently revisited other than a 5 minute visit to the docks.)
I loved DAO just as much as everybody else, but I can never shake the feeling that the music was so generic. I do agree that it had a very LOTR sound, and I think it worked against the game. DAO was the first game I played after going on a 5 year gaming hiatus, and even I coud tell that it wasn't very unique. (Am I the only one that hates 'Darkspawn in the Wilds'? Every time I hear it I have nightmares about the Kocari Wilds, the miserable 'I don't want to do this but I have to' kind of nightmare...)
I do admit that there were some stand-out tracks that I did like, such as Nature of the Beast, The Common Dwarf, and some of the cinematic pieces. But most of the ambient and battle music was just noise to me, and not memorable at all. Although my favorite track had to have been the main theme, though it would have been nice and dangerously epic to have it actually play in game.
DA2, while not the best I've heard, did well in that it had a distinct sound. While DAO was very high fantasy, DA2 sounded more unique, in that it had a highland touch, with some elements of folk in it. I adored those string riffs (as seen in Fenris Theme, Love Theme, those vocal tracks that rean't even in the game...) and the acoustic and natural sound the tracks have. I did like that there were actual character themes that reoccured (Fenris Theme (<333) Qunari on the Rise(<333) Arishok etc.) which is something I would have liked more of.
I do believe like it's predeccessor DA2's battle tracks were not memorable, and that is something I would definately like to see improvement on.
ALSO I do so love DA2's main theme as well, and again wish they would include it in the main game. AND I think iy would be great if the horn fanfare that occurs in both of the main themes could be a reoccuring thing throughout the series (Pretty please?)