Interesting thread. I do believe in synergy when using the same cable brand throughout, but there really are few manufacturers who produce quality ICs/Speaker cables and powercords (although the situation seems to be improving), especially at a price that is affordable. Asking a cable manufacturer whether there's synergy in their cables produces an obvious answer IMO. But I think the comfort in using the same brand of cables is that you know it'll work. You just don't know whether it's the best bang for the buck.
I use to own VD Nites and at the time, their powercords were way ahead of their ICs and speaker cables. I now use Jena labs cabling and when I first purchased their cables their powercords were quite a bit behind their well regarded ICs and SCs. So naturally, I have never had my system fully cabled by one brand. I believe having the same brand of ICs and SCs is usually a good thing, but I'm not yet sold on the idea of having the same brand of powercords as your ICs and SCs though. I am interested in hearing others opinion on this as I think most of us use different brands of powercords.
I use to own VD Nites and at the time, their powercords were way ahead of their ICs and speaker cables. I now use Jena labs cabling and when I first purchased their cables their powercords were quite a bit behind their well regarded ICs and SCs. So naturally, I have never had my system fully cabled by one brand. I believe having the same brand of ICs and SCs is usually a good thing, but I'm not yet sold on the idea of having the same brand of powercords as your ICs and SCs though. I am interested in hearing others opinion on this as I think most of us use different brands of powercords.