I had(past tense) a Delfina Lite until recently. It is a good card and AFAIK the only one with a working DSP. As for MP3 playback it is very good and works as advertied, MP3 playback with virtually 0% CPU load. The only short comming is it is slightly tricky to get it setup, but not too bad and the latest driver gives a "fake" crash window when playing mp3s.
If you can get one cheap, go for it.
