Okay, trying to do a comparison here - this is what I have done.
I have run two instances of Foobar, one setup for the USB DAC, one setup to output through my Audigy 2 using Kernal Streaming as I would do normally.
Starting the same song, 5 seconds after the other, and switching between the inputs on the amp at various points to see of the differences. My conclusion - currently I cannot tell a difference. If so, it is very minor, and in favour of the DAC. Whether or not this is to do with me reducing the output volume of the Audigy 2 so that it did match the volume of the DAC input I am not sure.
So, the DAC without Kernal Streaming and using DirectSound v2.0, if any difference, outperforms than my Audigy 2 using Kernal Streaming. I know this is not a fair comparison, so take what I say with a pinch of salt as I am not as articulate as I would like to be when it comes to describing the differences between sound.
I know most people view the Audigy 2 as something which would make their ears cry at the mere sight of the words spelling its name, but this is my current interpretation. I'm not deaf either I assure you. Upon visiting an audiologist I could hear the buzzing of his equipment on before he even began the test – apparently nobody had been able to do that before.
PS> Bare in mind that this is not my judgement of the AMP. This is my first interpretation of the DAC. The AMP is phenomenal.