Why does the copy sound better than the original

Al, I didn't take the time to read the threads you mentioned, but (my understanding is) this was settled a long time ago; and the overwhelming conclusion (at that time anyway ;~) had to do with the fact that a burned CD has (physically) real 'pits' -- which are actually 'burned' into the media with a laser, producing a more easy-to-read surface -- i.e., less digital 'jitter' in the resulting datastream.

Commercial CD's are stamped (ironically, just like an LP!) so their so-called 'pits' are really just depressions (or was it bumps?) that scatter the reflected laser light enough to make it look ("read") like a pit to the playback sensor. Whereas a recorded CD (with 'real' pits, literally burned into the surface,) produces a much cleaner (jitter-free) signal on playback.

Probably ripping software is doing a good job there. :)

Cd-rs have an ink layer that is darkened by a writing laser. My experience with cd-rs is they become unreadable if they are exposed to light over a period of time. You can leave one sitting in the sun to demonstrate this effect in a shorter period of time.

An interesting experiment would be to make a copy of a commercial audio cassette. If the copy sounds better than the original cassette would that automatically eliminate fuzzy pits, jitter, wobbly discs, black CD-Rs, crappy CD players and scratched polycarbonate from the list of candidate explanations why copies of CDs sound better than the originals? No, not really, but it might be an indication, some evidence, that there's something else going on, something much more mysterious, more, uh, disturbing. Anyone STILL not see where I'm going with this?

I do see where you're going with that.
Which is the part that's really disturbing . . . .

Anyway, it's apples to oranges