I'm not dreaming - these are great CD copies

"REd book" cd = the standard cd protocol (you know, 44.1kHz /16 bits, the works).

I am so happy to see this discussion take place. In order to have the best quality sound that was for me pocket portable for travel I was in the habit of ripping music lossless to the Microsoft Zune application on my notebook PC to play on my 80 GB Zune player while traveling. I had burned a number of CDs from that source when I was unable to find the original Redbook CDs to play on my home audio equipment.

Even today I had the experience of listening to a burned lossless copy of Shostakovich Symphony number seven and was absolutely blown away by the quality of the recording, way beyond what I had remembered. In this case the original was a Naxos CD which is, because of it's price point, I'm certain not the best pressing that one can imagine. What a very timely discussion that has now confirmed something that I had been feeling but had no way of even imagining how to explain. Thanks much to the OP. 
 

Equalizer settings left on can account for a mysteriously "enhanced" sound. 

Can you really improve the quality of music from a red book CD by simply copying to some other format?

No. Data on a red book CD is stored as a cda file. As such, copying a cda file results in the same cda file being copied elsewhere. Ripping a cd on the other hand can result in a change of format, such as wav. Once in an editable format such as wav, the file can be reworked in the digital domain and as such can be improved (subjective) relative to its parent source file.

I thought Audioengr (Steve) had commented about this in another thread some time ago. My recollection is he said copying the CD onto a CD-R eliminated one contributor to jitter (I don't believe it eliminates jitter in any absolute sense).  If I recall correctly (and that ain’t anything to bet on) there’s less (imprecision?) in how the dye-based copy is read vs how the laser beam falls on the "pits" making up the stamped CD’s information.