>I cannot overstate the drastic difference in quality.

Quality is governed by your subjective experience. The HD1s are tuned in a way that, paired with the Vestri and the files, creates the experience that you enjoy better. That's it. It's not about "better quality" and definitely not about "fidelity."

You also paid probably $99 for something that Apple perfected and sells for $10 -- that USB DAC. Which is fine! You should spend money on things that make you happy.

>The quality of audio that folks were generally listening to in 2005 was better than what we are doing today.

This sentence doesn't have enough detail. What is quality supposed to mean here?