Comparing Auzentech X-Fi Prelude and Asus Xonar D2 for a HTPC

[Subterranean]

I'm looking to build myself a Media Centre/Home Theatre PC and obviously the sound card needs to be good quality. I've seen good things said about both the Auzentech X-Fi Prelude and Asus Xonar D2, but have not seen direct comparisons yet. Does anyone have any view on these cards, in the context of a HTPC, ie no games (i already have a good desktop/gaming pc).
Thanks for any advice.