Since you changed your post, I guess I'll respond to that too
"paul_b_18-ga" has one of the most oft-repeated misunderstandings about digital versus analog sound, that digital sampling throws out information that records perfectly preserve. This is untrue.
While the process of sampling does throw out information, so does the process of putting something into plastic. Grooves can only go so deep before the needle gets stuck and breaks. Only so much information can be packed in before the valleys and troughs become smaller than vinyl molecules. Dust, broken pieces of vinyl, warping, and pressing errors introduce "noise" that often overpowers the signal.
This is why vinyl is so bad. Sounds quieter than, say, 50 dB below peak, just can't be heard because they're overwhelmed by noise. To compensate, you have to significantly compress the audio (increase the loudness of the quieter noises) so that these will be heard and not fade out entirely. Also bad for vinyl, if you're playing a record at around 100 dB, you have at least 30 dB of constant noise and hiss, more on cheaper equipment or an older record.
Again, CDs aren't perfect and do have problems, but again, these imperfections aren't noticeable until you crank the CD up painfully loud to begin with, and are likely to be smaller than the imperfections in your sound system. As I stated before, CDs faithfully record over 100 dB of dynamic range.
The only other benefit of vinyl in that thread, by rayljr-ga, is that records can theoretically hold information above 22,500 hertz, whereas CDs clamp them here. While these frequencies, individually, are inaudible to humans, recent research seems to imply that we can hear the effect they have with other, lower frequencies when played simultaneously.
Of course, as rayljr points out, you need a really expensive needle and system to pick these up, but also a record that hasn't been played more than a few times before, since needles will eat away at this information after a few plays.
The only genuine solution to hear these is to go with SACD or DVD-Audio.