Postscript
NORDOST does have dealer demo cables available (they have a green sleeve).
Your existing CARDAS cables are fine cables themselves, full stop.... you are not considering moving up from Home Depot POS quality level crap. What’s driving the possible change? A brief summary of your system components would help.
My experiences showed that a full FREY cable array (ICs and speaker cables) was the strong leader choice, when compared to an ad-hoc swap-in of just the ICs or the just speaker cables alone.
If you cannot arrange a personal take-them-home overnight audition with the demo cables, or even have an at-the-dealer personal audition, then I would heartily recommend a phone or email consult with a NORDOST dealer that carries both brands for his two cents worth.
FWIW, up here in Toronto, AUDIO EDEN carry both and will give you a fair and even-handed comparative opinion on the respective cables and hopefully answer your questions better.
Audioeden.com