You seem to be ignoring one key part of mine and Thisispains posts. We are saying that the audio should be the same no matter what you use, as it technically should, the 1's and 0's are only meant to interpret in one way (based on codec used), and will produce the same analogue waveform no matter what. But the quality of the DAC in a SPU will affect how the waveform comes out (frequency limits, amplitude limits), and any other "enhancements" on the SPU being used will also affect the output. Not necessarily for the better.
But we are both 100% correct when we say the audio should always be the same thing no matter what interprets it as it can only be interpreted in the same way it was encoded to make sense.