I've been experimenting with various settings for foobar2000 over the last couple weeks.... So far, of the more esotoric settings, I've tried Kernel Streaming with upsampling to 96k, various methods of dithering, and also ASIO4All output. Thus far, I haven't had much luck finding a setup that I like the sound of without hammering my computer - I'm running a 700 mhz duron overclocked to about 1.0ghz, so I don't have as many cpu cycles to play with as some.
I was wondering what settings people had experienced good results on, particularly with the chaintech card - I'd love to find a decent sounding setup that wouldn't have me running 50% cpu utilization all the time... From my reading, I thought ASIO4All might provide that, but I can't get it to work without using foobar to resample to 96k, so it seems like there aren't any real benefits over normal kernel streaming...
Kernel streaming and ASIO both output directly to the soundcard, so if properly set up they should sound the same. DirectSound is purported to be better on Win2k/XP than WaveOut, but I believe both go through kmixer and alter the sound slightly.
I'd say if you're undecided, just use kernel streaming or ASIO without any upsampling or dithering, and enjoy.