Are you speaking of the power cables? I also have the Sigma NR V2s power cords. They are pretty decent and are as you describe.
My original benchmark for power cords was Neotech which seemed to be the OEM supplier for many cable companies over the years. The Neotechs are pure OFCC copper and had Neotech plug connectors which were also Neotech OFCC copper.
Shunyata actually measures their cable for noise abatement and provides those measurements in their research papers and published videos. To me, this is when you know what you are getting.