Are NBS cables are sound better than Nordost ?

If low end NBS then don't bother. Omega I and II are pretty good.

I suppose it all depends on the complementary gear and your tastes. In several tube-based systems I've heard them in, the Nordost speaker cables and interconnects sounded a touch bright and harmonically lean. But, this was probably a system-dependant phenomenon.

I personally like the NBS line of cables. Their different lines have a different sound, so, if you work with a dealer, you can try different cables to dial in what you are looking for. One word of caution, don't try the Black Label stuff, it will make you disappointed with almost anything else.

Other cables I personally like are: Basis (the turntable manufacturer), XLO limited, and certain Audionote (uk) cables.

Larry is absolutely right about the Black Label, we tried a lot of Power cord but none can compare. My friend have about 5 of them in his system. The solidity of the image, the body and weight, the silence. I just wish it is not as heavy and rigid and expensive. Sometimes you wouldn't use it just because it is so difficult the work with.