Nordost or Alpha Core?

No, you shouldn't worry about oscillation. There is a review on ultraaudio.com about the Veracity speaker cables and interconnects. It is rather hard to distinguish the Valhallas from the Alpha Core on digital sources. HP had the same issue years ago, and found that, if used on analogue, it was clearer to distinguish the two, but on CD, not at all. He DID, however, have the Veracity top of the line. I own the Alpha Core AG2 (speaker cables) and they are quite transparent-sounding. Low level detail is excellent! I had them at the same time as I owned the Valhalla: I had trouble telling the two apart, to the point that I thought I had the Valhalla in the system when I had the AG2 interconnects. And the AG2 was not thin. \
By the way, I also had the MI-2, which I used on the bottom of the Alon Viper Elite speakers. Pretty nice!

The Alpha Core 'wire' is very hard to beat. As Clio suggests, the supplied Zobel should prevent the already unlikely occurance of oscillation.

The Alpha Core is one of the best values in speaker cables IMO. Any concerns about oscillation can be remedied easily by having Alpha Core supply you with the Zobel networks. I believe they supply these for free upon request.