1s are 1s, 0s are 0s, right?

Unsound...The electrical signal that transmits digital data (a pulse train) can be greatly distorted, and the receiver can still reconstruct the original data perfectly,

Your example: 010101 vs 0 1 0 1 0 1. I believe you are thinking of jitter.

How about 16 bits: 01 0 10 1 0 1 01 01 010 1.

If the receiver outputs 16 bit words to its D/A at uniform intervals based on its own clock, it doesn't matter how irregular the incoming serial data transmission was.

Furthermore, some of the zeros can be misread as ones, and the correct original word can still be recognized, thanks to the error correcting encoding of the data, but that's another topic.

I am quite happly with my system's audio quality and I don't feel the urge to spent $6000 or so to find out if an esoteric player would sound better. (I have other interests to spend money on).

It's true that my experience with digital communications is in the context of very high-tech military equipment (missile guidance systems) and the techniques that we use may not always be utilized in audio equipment, although I can't see why not since the cost of doing things right would not be great.

In summary, to address the wrong ideas that I hear most often...

digital pulse distortion, be it pulse shape due to line reflections, or timing (jitter) should have no effect.

Error correction is not bad. The purpose of error correction is not to correct errors. It is to permit higher bandwidth communications by operating the hardware so fast that (correctable) errors do occur. You give away, say 50%, of your bandwidth to redundancy, so that you can run, say 5 times, faster.

D/A non-monotonicity would cause audible distortion, but I am not aware of this being a problem with modern electronics.

nonterminatingdecimal@hotmail.com....Exaxtly.