I have been using the ordered Shunyata Altaira Chassis hub for two weeks now. I have connected all Sigma ground cables behind a chassis screw of my devices. There are not that many so that 1 hub is enough. The devices are Vivaldi DAC and Clock, Auralic Aries 2.1 streamer and the PasLabs X-250.8 power amplifier. After plugging it in it sounded only partially better, sometimes thought, is this it now? Now, I can confirm that it will only get better after about 5 days. And how does it sound now? My biggest upgrade in years. For a description of what to expect I refer all the way to the test above, and if you have the opportunity, try it in your own set. Mine will never go away.