which sound card is better?

[HostileReality]

I have a creative x-fi xtreme music card which i got because my machine was built as a games machine primarily. But I ended up selling my music machine and combining its Hard drive with the gaming one so that i can make music on the best computer. Anyway, i also have an m-audio delta 2496 card.

My question: will the delta have any advantage over the x-fi? im not bothered about inputs, mainly just the quality and convertors etc.
I kind of want to keep the x-fi as its good for games, is it possible to install 2 sound cards in one machine? (btw im pretty good on computers).