What is dual mono and how is it better than stereo?
100% channel separation
And what is balanced output & how is it better than unbalanced in terms of listening experience?
A fully balanced circuit delivers pure sounds as the receiving end knows what is the sound signals and what is electromagnetic noise.
If I may add a word or two to Venkat's explanation: it "knows" what noise has been picked up
by the cable. By subtracting the noise, as Venkat explains, what you eventually get at the destination device is what left the source device.
Is it better? My
opinion is that it is a superior design, and is a proper piece of engineering, whereas "single-ended" RCA cables are more of an accident of history. It is intended to work in studios where cables may be many metres long, and in auditoriums where they may be even longer. Will it make a difference for a 0.5m interconnect? I doubt it very much.
Another thing about pro, balanced connection: the levels are quite a lot higher.
My choice: always try to connect balanced to balanced, unbalanced to unbalanced ---although conversion is possible--- and, if balanced inputs and outputs are available, I'd choose them over the unbalanced sockets on the same kit. If only because I like the theory
.
Do not try to use balanced cables to connect unbalanced equipment. There cannot be any advantage, and there may well be disadvantage.