power cable length importance

Filtration? I'd suggest the advantage of a shorter power cable is that it is less of an antenna.

Dancer: 500$ worth of Monster? ouch. Balanced cables have an advantage in noise rejection and are therefore worth it to some. Inexpensive, or not wacky expensive, at least, cables are easily found....Guitar Center, for example.

Microphonic power cable? And worried about its resonant frequency? please.

Monster Sigma are not that bad especially with some speakers; in fact, can be quite good. I heard them.
Price is not everything sure, some cables are very overpriced.

If some of the internet buzz is true and ESpecially the letter exchange with BlueJeans, I'd disqualify monster simply because of poor / predatory business practices. Regardless of price, which I think can easily be beaten at any performance level by several others.....