Nordost flat line cabels vs norse series

What are the sonic character differences between the Nordost flat line cables and the Norse series? In particular I am interested in anyones experience with Red Dawn vs. Heimdall interconnects. Thanks.
I currently own a mixture of Blue Heavens (which I'm phasing out - only one pair left), Red Dawns, and Heimdalls. In my system, I heard real improvements with the Heimdalls over the Red Dawns (which were only a marginal improvement over the Blue Heavens). The Heimdalls are more transparent, reveal more detail and depth/dimensionality, and have excellent transient response. I now intend to upgrade all of the cabling in my system from Red Dawns to Heimdalls, which are by a significant margin the best cables I've ever heard (or not heard...) in my system.
Sdcampbell, may I know if you are referring to the speaker cables or interconnects?
I bit new info to this thread. I think I have about 100 hours on Frey IC and the good thing they are burned-in enough not to think too much about heimdalls. Frey are very fine cables, and hour after hour they show more and more of their character. Less bloom compared to heimdalls, but more crisp details, which are still very rich in tone and thats amazing thing. Now rarely but sometimes those details appears bright, but if this dissapears with additional hours of burn in, I really going to love freys even more. 3D soundstage, instrument separation is another huge step forward. You cant go wrong with these fine cables (heimdal, frey) - they are the real deal, true hi-end (well for $999 MSRP/Frey they just have to provide something magic). I am really in good relationship with a dealer, but I am bit scared to try migthy Valhalla, the price tag is not unreachable but crazy for sure.
I've demoed many times the whole Norse series in the same system and every step up in the series is an upgrade in the performance, so the Heimdall is better than the Baldur, the Frey is better than the Heimdall and so on.
BTW, as already pointed out, the Nordost cables should be breaked in with the Vidar or it will takes forever to show the best performance. I strongly prefer and always suggest to wire the whole system with the same series of cables (Nordost or not, no difference here) because I feel that it sound more coherent. And, Nordost cables are not forgiving on system's fault.