What is 'LowZ/balanced equipment' ?
It isn't about the cable, it's about the interconnect system.
1] RCA to XLR is always as good as RCA to RCA, and sometimes better.
2] XLR to RCA can be tricky and often is.
It is pretty simple actually.
In an unbalanced circuit, the signal swings +ve and -ve above ground.
This would be a typical circuit.
You can see that the input is connected to pin 3 of the op amp. The impedance is set by R1 L which is 47 K, and this is a PU front end.
In a balanced circuit the signal swings +ve and -ve around ground.
So if a sine wave were presented the +ve part of the wave is connected to pin 2 of the op-amp. The negative parts of the wave is connected to pin 3 of the Op-amp.
So they swing negative and positive above ground and so are balanced. If pins 2 and three connections are reversed there is a phase reversal just like reversing the connections to a speaker.
The input impedance of these circuits is generally around 600 ohms.
The main advantage of these circuits is noise cancellation which is really important in microphone connections, or other long runs.
Since the wires connected to pin 3 and 4 are identical except for their color, they pick up any noise and interference equally. Since these voltages oscillate equally above ground connected to pin 1, the noise is cancelled out at pins 2 and 3, as the interference in the wires connected to lins 2 and 3 are 180 degrees out of phase and therefore cancel.