Nordost Norse 2 series vs Shunyata zitron

You have highlighted the conundrum

(1) Unless the A-GONER has your identical system, all you going to get here is purely anecdotal and extremely biased personal value judgement testimonials, that have zero bearing and likelihood of similar success in your system.

(2) The tension is further magnified by dealers pushing competing proprietary product that, again, has no assurance of working best in your system without actually auditioning them.

YOUR TAKEAWAY:

There is no substitute for a hands-on auditioning in YOUR unique system; because "one size does not fit all". Regardless of the pedigree, it may sound fine in the showroom or in a buddy's system, but it may sound like crap in your system: system synergy matters - BIG TIME! There is no substitute for doing your own homework.

let's all remember that this hobby is a journey and not a simple dial-up destination exercise.

I have the Frey 2 and the Tyr 2. I also have Shunyata speaker cable, power cords, and Nordost power cords. And I had, for a short time, Shunyata's Zi-Tron Cobra (to match my power and speaker cables).
They are both excellent cables, but are you speaking of power, interconnect or speaker? I don't have Nordost's speaker cables, so I'm not qualified to answer that, but I will tell you that you cannot go wrong with either interconnect or power cords (my Nordost power cord is not a series II).
The Norse 2 line is excellent - even magnificent - in all frequencies. Dynamics are, not to put too fine a point on it, astounding.

Now, here's the catch: the interconnects are Nordost. The power cables and speaker cables are Shunyata. Could I tell you that the way my system sounds is due to the Nordost interconnect? Yes, without hesitation. Could I also tell you it sounds fantastic with the Shunyata power cords and speaker cable? YES. I'm sure I could get a "richer" sound with the Shunyata, as that seems to be their forte. I will say, however, that the current line is not as full in the mid bass as the older lines. I hope you realize that what I'm saying is nothing new. Read Robert Harley's review or the Editor's Choice and you'll see that he said the Shunyata was more "midrange and treble oriented" (meaning, it is clear that they went for excellent, clear bass, but with less power - or "slam," if you will - than the previous lines. Soundstage.com noted the same thing, so I'm not alone in my perceptions. Yet, if you were to put in the Frey 2, as I have, with the Shunyata speaker cables, you would NOT be unhappy, not unless you NEED that earthquake-type bass so many people are fond of. And which doesn't exist in most concert halls, but hey, if you listen to heavy metal, you might just want the Nordost stuff. I'd say it's slightly more even, top to bottom, IN THAT ONE - AND ONLY THAT ONE- sense. So you will likely get a bit more "slam" in the mid bass with the Norse 2 line. I sure am. My Tyr interconnect, series 1, didn't haven't this kind of bass, I'll tell you that!

If you're not sure, just buy it new from Music Direct. 30 days, no re-stocking fee and they're great about it (and believe me, I've returned a LOT of stuff that I just didn't think made my system sing). And they were not happy with me. But THEY TOOK IT BACK ANYWAY. And, as a result, I buy from them still (much to their consternation, I'm sure) including sending back some Stillpoints Mini Ultras just today, because Bruce at Stillpoints said the Ultra Minis wouldn't handle 90 pound speakers . So, I got the Ultra SS instead.
If the Shunyata interconnects match the speaker cables, they're fantastic, too. But for now, my system is 70% Shunyata and 30% Nordost. And while I'm sure Roy Gregory is right about complete cable looms, I've had a complete Valhalla (interconnect, speaker cable and power cords) and I'd say the system I have now is better than the one I had in 2006.
What's the rest of your system, if you don't mind me asking? It's easier not to speculate in a vacuum (meaning, not knowing the rest of your system).
The short answer is: they're BOTH great.

shotgunned NORDOST Frey speaker cables (independent 4's doubled up to now be 2's): matched shotgunned jumpers

the improvement from a 'shotgunned" over a "standard" two-cable run is clear in my system
FWIW

I'm using Dynaudio confidence C1 mkii with PSaudio PWD MKii and Ayre AX-7e amp. I'm using them in a nearfield (8 feet) listening environment. I'm after dramatic dynamic swings, a black background and a neutral sound that isn't accentuated (or accenctuated evenly ; if you're a glass half full kind of guy) in any particular respect.