I had them in my setup for about a year. Good cable but as you stated a rolled off high end (I may add also rolled off bass). Since you like cardas why not try the golden cross or golden reference (personally I think the AQ king cobras are better than the NR)? Because of the NR's I personally have never tried any other cardas cables. I have the fusion audio interlocker now and am very happy.
Cardas Neutral Ref ICs time to change??
I have used Cardas Neutral Reference ICs for about 8 years between various CD players and integrated amps or power-pre amps. Right now it is a Sony SCD XA 777ES and an Exposure 2010S. I find the Cardas to be very detailed and clear but in the times I have tried other IC cables I have found that the others (Analysis plus, Audioquest ect) tend to have bigger stages and more HF extention with slightly more fullness in the bass. and not sound as mechanical. I do always end up sticking with the Cardas and I am not sure why. Opinions on the Cardas NR IC would help. Thanks,keith