Dave, either I am confused or you are, maybe both! :)
But (to me) the sound card has nothing to do with ripping CD's, it is just for sound playback on a PC; you can rip all you want without a sound card.
Furthermore, as I already stated as about as clearly as I can, which may not be saying much, when making copies of your CD's, the only reason they wouldn't be bit-for-bit copies would be because of defects (scratches) in the CD, and if that is the case, your transport will also have the same (error) issue.
When a CD is read on a CD transport it is read one time and sent to the DAC. The benefit of using error correction when making the copy is it reads many times to get the best accuracy, meaning the "copy" being read can have the potential of being read better than the CD copied from.
Stereophile had a very good article months back on digital and talked about it staying the same as long as it stayed in the digital domain, as it should, it is when brought into analog where the issues can ocur.
Your issues of having the re-rip some CD's is rather odd to me as well; I have not had to do this at all. I also ripped many CD's prior to turning on EC and I have no issues with them nor do I hear any diferences with those.
maybe the cd2 is just a very synergistic match with the dac 3, they were made for use with each other.
I don't see why this would matter. Like I say, I haven't a clue of why you guys had the results you did, all I can say is this differs from others, for what it is worth.
Thanks for the clarification on the exaggeration comment; I wasn't clear on the intent. I am aware of the exageration(s) we 'philes can make, but for me there was none. Like in your case, I brought over another set of ears who agreed that he could no way tell a difference in our comparisons. (In some intances, like comparing the CD to the iPod combo, I could switch inputs with a touch of the remote, with the inputs being level matched; neither of us could accurately pick a source.)
