Wow, I have trouble wrapping my brain around how power delivered over the last 3 feet thru an uber expensive cable of "better quality" than the 28 miles of cable between my house and the hydro electric damn is was generated from can be any better than a generic cable of the same quality of cable.
It is probably fair to say that the long haul wiring is effectively thicker than the house wiring and the power cord simply because it runs at much higher voltages.
That said, what I always struggle with is house wiring, which runs at the same voltage as the power cord and uses relatively thin (and cheap) wiring.
