Wire is application specific. In some applications silver sounds much better than copper, in others copper is better than silver. Then there are those applications where a combo is good. Question then is: how much silver to copper? Stranded or solid?
The big wildcard is the wildly different SQ of allegedly "pure silver". This leads me to wonder if the minor percentages of entrained metallic contaminants are responsible.
For example: I know the differences between ferrous and non-ferrous contaminants. Iron sucks.