Yeah Cerrot, something just isn't adding up. You bought a $4500 Integrated amp, listened to it through SPDIF and found it involving and emotional, and then you returned it? I assume this to be the case, because you no longer have it, and I'm doubting you carted your Gateway PC to a dealer. If it belonged to your friend, and he still had it, obviously something was working right for him - why didn't you judge it in his system, rather than cart all that equipment to your place in order to judge it on your computer, a component that can swing the results wildly in either direction if not setup properly? It just isn't making sense to me.
Maybe your issues with USB are an issue with either your computer, or the way you're outputting the audio from the computer. Even forgiving the inane hyperbole in saying that you can get better sound from a string than from USB, your anecdotal evidence just doesn't add up for me. And even if I accepted all of it, that you bought a $4500 integrated amp, found the sound involving and emotional through the input of your choice, yet returned it because you didn't like the input that you would never have used anyway, there are too many variables to account for why you're getting "garbage" and other people get great sound. You want to write off all USB implementations, and I'm not ready to go there yet.