I have done much research and experimenting into this question.
My experience thus far; All the research and info on the web and at the libraries aproximates the comments on this post -- theroretically is should be possible to make an EXACT copy, in reality, most can hear a difference.
In my experimentations; I have used gold medical/archival grade CDRs, many different CD & DVD burners, burned at true 1X to many X speeds, have used Mac, have used PC, have used EAC, Nero, Max, etc software, and have even isolated computer parts (CD burner, PSU, motherboard, HD) and have used several types of shielded & unshielded cables within the computer.
I have A/B the products with the originals to family and friends. Audiophile, non-auudiophiles, young and old.
The results thus far: #1. I have had a few improvements -- in 100% of such cases the original CDs were from small-time producers from local/regional bands. #2. I have come across 100% failure in besting a original CD produced by a national/international producer (Sony, MFSL, Rhino, etc). #3. I have experienced very poor results in matching national/internation producer quality.
My two cents from my idea that I could burn all my CDs onto hard drive and Squeeze Box + DAC to the main system. After this year long craze of experimenting, I'm continuing on with ole factory CD - I'm not convinced...