Ron there are better feet than the stock feet, and we are talking about an aftermarket power cord as well as a high quality usb cable, we actually have the best USB cable on the market and it is not from a traditional cable company and we do recommend a high end ethernet cable as well.
So we have a series of products we recommend that gives the best sound of the Zennith.
You were correct about everything, the Wireworld Ethernet cables did make a noticable improvement as well.
For all of these reasons we said to PM us there is a lot to go over.
Dave and Troy
Audio Doctor NJ