I think if we could adequately explain the reasons why we hear what we do in engineering terms, it would already have been done. I think we can say that the current measurements of capacitance, inductance, resistance, and physical characteristics of guage, stranded vs solid core, shielding, type of metal, physical layout, dielectric, etc. can explain some of the differences. And yes, there are tried and true reasons why excess capacitance leads to one type of sound while excess inductance leads to another. The interaction with transformers and other electrical components would probably not be poo-poo'ed by any engineer, because this is explainable.
What isn't fully explained is what combination of the above traits will work best (and best may be only defined by our own ears) in any given situation. This is not scientifically available to us at this point. There is also a very real possibility that some type of new measurement unit to help explain it has not yet been defined.
Are these cords filters - probably to some extent. Are the boosters of some characteristic of the sound - probably to some extent. Do they make a difference - yes, to many ears. Why is one better than another in your system - who knows? But the same could be said of one amp or preamp or CD player over another, or one interconnect over another, or CD vs computer based digital playback (where the digital bits are identical based upon currently available measurements).
Hopefully this inadequate description of the variables involved makes some sense. In any case, like in anything, try it for yourself and let your ears decide. Even if you hear a difference it may be insignificant to you and not worth the cost, then again, it may be well worthwhile, or it could point out flaws in your current system that you didn't hear before ("... and I'm on the road to find out", e.g. Cat Stevens).
Bob
