Quote:
Without beating the corpse of this horse too much further into a pulp, I am curious why there is a difference? Analog v. digital signals?

The difference has a lot to do with the higher bandwidth digital signal. Interference, crosstalk, and signal attenuation are a big issue when running at gigabit speeds, and the higher quality Cat-6 cables contain correctly-twisted pairs of conductors and use higher-quality connectors.