You have mentioned some of the better powercords and as will always be the case with cables you have gotten a mix of feedback. Since powercords have a tendency to like certain components I will just mention the powercords that I personally like on the Wadia 860 and the PS 300 & 600.
On the Wadia 860 the best three powercords that I have heard are the Shunyata Python retail $1000, The Audio Magic Clarevoyant at $1500, and the Synergistic Designer reference
at $1400 not the $2000 Square.
On the PS products the Whale is good its advantage is that they can be picked up cheaply because they are sold direct, but the Designer Reference Square retail $2000, and the Fat Man at $2500 to $2750 depending on version are by far the best next to the insane Khan at $4500. An inexpensive powercord that is very good is the Shunyata Sidewinder Gold at $350. But Audiogon usually has many of these powercords at good prices.