The price of Gold has rocketed of late, the UK are trying to take the surplus cash from their gold reserve fund and use it to relieve third world debt, but it seems that's not high on the US agenda. That aside, there are some interesting properties of gold when used as a conductor. It has a higher resistance than copper and silver and is therefore supposedly inferior as a conductor. Yet it has superior corrosive properties, therefore the inference is that it's sound will remain consistent for the duration of it's life, whereas copper and silver might me more prone to deteriorate due to the effect of corrosion and how the corroded layer creates unwanted skin effects and negative interaction with the insulator.
My understanding was that gold slightly attenuates the frequency extremes, and as s23chang say's gives things a sweeter sound.
The cable I'm using did indeed sound a little rolled-off at both ends initially, but surprisingly is starting to open up, particularly on the higher frequencies. This thing has a lot of potential and I can't wait to get another 100 hours on it.