I'm in the process of picking components my new core 2 duo build, and was planning on buying a x-fi xtrememusic card. My main concern is the sound quality of music and videos, since I do not game much. I listen through two bookshelf speakers, powered by a panny xr-55 reciever. The motherboard i'm getting (Asus P5B) has an S/PDIF out, which got me thinking, will buying the x-fi and using it's digital output give me any improvement in sound quality? Or should I just use the S/PDIF on my mobo?