My opinion
There are several thoughts on the subject, and you will probably hear them all... conflicting.
To me there are several aspects to the converters and front end to any recording setup. There is the converter itself, some chips are better... how much better?... the better ones have less errors in their calculations that can translate to clearer image. Then there is the clocking mechanism. The better the clock the clearer more focuses and deep the image. Many feel the clocking has more impact than particular chips. Then there is the analogue circuitry at the fron end or rear end after the chip. If you have cheesy wiring and components, it will affect the sound.
Of course the pre amp and signal path prior to the converters is very important.
Not knowing what total signal path differences there were from your rig to the apogee rig, there may have been a combination of things that simply were better.
Having said all of THAT, I run a double Delta 1010 rig synched with a Lucid GenX master clock. I recently upgraded to a Lucid D/A for playback / monitoring (all clocking from the same source). The difference was VERY apparent in the clarity of my allready recorded tracks.The Lucid is quieter and clearer You can A/B through the Deltas and the Lucids and the same tracks sound very different.
That tells me the Deltas input conversion is better than the playback section, I simply was not hearing the quality of what I DID record. I wish I could record the same thing through 2 different converters and listen to side by sides for comparison.
I am going to purchase at least 2 channels of Lucid / Apogee type quality and see what the difference really is on my existing set up.
That probably does not help much but it is a jumping off place.
Tom