Asa, I agree with your Nordost opinion. I ran Nordost QF for around 2 years, and did not make this realization until I tried other ICs. I do not think that I could state as eloquently as what you said about Nordost. I tend to describe the QF as having the effect of filtering music/signal. This filtration does make the end signal sound perhaps a bit cleaner (MP3 is effectively a filter as well that makes CD digital sound cleaner, as well as the CD medium itself is a filter for analogue sampling the wave at 44khz or so), but there is obviously detail that is missing from the QF when compared to other ICs. I have not tried the Valhalla IC, so I have no opinion of it. After hearing the Valhalla SC, however, I can imagine that the Valhalla IC is very good. My personal favorite IC now is the Jena Labs Symphony. The Jena Labs is no nonsense ultra ultra pure copper which is cryoed with no gimmicks. It has a transparency and a naturalness of sound that I have not heard in any IC that I have tried in it's price range ($1100/3' retail). Even at full retail, I think the Jena is worth every penny.
KF
KF