RE: ... the setup uses only silver wire on the anode side but not the cathode side?
A. That's a good observation. The stainless cathode was likely part of a cost driven setup. And so I'll edit the parts list in future posts to avoid confusion.
RE: If that were the preferable method, why does virtually every other electrolysis type Colloidal Silver generator (actually ionic silver) use silver for both?
A. For simplicity, I'd say the ideal would be the use of silver all around, as this would eliminated the potential for mismatching electrodes. Though it remains that the cathode has no part in the donor process and that these could be either; stainless or copper in cases where costs are a priority.
RE: There is a huge difference in conductivity between silver and stainless steel.
A. This is true. though this could also prove advantageous to use an inferior cathode to anode ratio.