IMHO... Its all about conductivity. Most of the stock jumpers you see are plated with nickel which does not give you the conductivity you get from pure copper, gold plated copper, silver plated copper or pure silver. Nickel may have a sound characteristic that people desire, or are use too, in some amps, (there lies the subjective nature of wire) but in my experience, the better the conductor = a healthier signal to amp = improved sound stage. Even cleaning these in out jacks makes a big difference. Again, this is just my experience with my ears..
James
James