The most obvious improvement is the bass extension.

Long break in

I am glad to report that, after more than 2 months of breaking in, STEALTH Ultimate Ribbon loudspeaker silver speaker cables are the overall winner as compared with my previous NBS cables! The most obvious
improvement is the bass extension. It went deep down and with more details. I could feel the vibration of the hands beating the drums. The effect is more live-like! For the mid and high frequencies, the difference is not that great.
Overall, STEALTH cables sound more clean and natural! I have no regret at all buying these cables. Congratulations to you for making these an excellent product!

If I may add my comment about the Ultimate Ribbon silver speaker cables, it also gives better scale and wider sound stage. I have a feeling that STEALTH silver cables still have room to improve with longer time of breaking-in.