if a certain component is better/more efficient/more powerful than other component? And the question was about the component for SPDIF in vs the component for USB in, in the Marantz ND8006 which described above.
There's kind of two ways to answer that. There's the pure technical design, where USB and coaxial S/PDIF have different trade-offs, even if both are implemented perfectly. And then there's the practical implementation of your specific products based on the product designer and manufacturer, where things can be done better or worse, or have their own trade-offs.
So, while from one perspective you could say something like chip/technology X has better specs or features than chip/technology Y which might lead you towards a default view that X is better than Y, what happens in reality may differ and only be something you can determine through thorough simulation and measurements or by listening (while being careful about psychological biases). Plus environmental factors can contribute, perhaps intermittently (e.g. power sags, EMI).
Of course, we all do start with comparisons of X and Y because we need a place to start when making decisions and trying to evaluate things.
Sorry it's not a clear answer to your question. Going back to your original post, while you have a preference that is split between the two different inputs, it's possible that one of the two is more accurate and precise despite your personal preferences, or that the characteristic you like in one input is what makes it not possible to produce the characteristic you like in the other input. Meaning you cannot actually have both because they are mutually exclusive / incompatible.
