56 Strand was a general purpose 4mm2 hook up wire you would twist into pairs. QED 79 strand is 2.5 mm2 so not as good as the RS cable but easier to handle. I still use QED 79 Strand. Thinking back I should have nicked some of the RS cable from work, we used miles of it
. I did borrow some Litz wire at some point but never got around to trying it 
I'm a musician, so I have a bunch of Pro-AUdio gear and I know Furman products on the pro-audio side of things. I know the power to my house is not the greatest. Lots of noise. So the improvement I claim is that adding this unit to my high-end gear reduced the noise floor thus making the audio sound better. So, That's why. You can read this but the only way to really know is buy one and test it at your location. Either it sounds better or it doesn't. That's how I measure.
I asked because I wondered how one might test the power supply from the wall outlet, and what to look for, what thresholds to apply. I am unable to hear any noise or distortion from my stereo system itself, but everything is plugged into a couple of decent surge protectors.
Get one of these from Amazon, easy to use, just plug it in your outlets and it will show you the noise level. You can even plug it into the power supply your equipment is in and see which piece is causing the most noise by the process of elimination.
For XLR balanced cable, starquad type cable is superior to regular balanced cable. Starquad geometry sends signal over 4 wires (A pair of twist wires for plus, A pair of twist wires for negative, 1 shield). I have used them for proaudio installation and its noise rejection performance is pretty good. Splicing and soldering are a bit hassle compared to regular types.
