Audible Differences in DAC's? Options

[sawdin]

When he announced the release of the ODAC, NwAvGuy posted the the following on his blog:

NO SNAKE OIL REQUIRED: Many audiophiles want to believe more elaborate or exotic DACs offer higher fidelity. The ODAC demonstrates you do NOT need any of these for 100% transparent performance:

Asynchronous USB
UAC2 (USB Audio Class 2) Support
Asynchronous Sample Rate Conversion (ASRC),
Minimum Phase Filtering (no pre-ringing)
Non-oversampling NOS DAC chips
Dual DAC chips
Balanced Outputs
Vacuum Tube Stages
Elaborate and/or High Current Power Supplies

Is his position accurate/defensible?

If there was a well-designed DB/ABX test of the ODAC and sub $500/$1000 DAC's (e.g., Audioquest Dragonfly, iFi Micro iDAC, Audioengine D1, Emotiva XDA-2, etc.) that are are Asynchronous, USB Audio Class 2, etc. etc., do you think there would be 'audible/discernible' differences?

The reason that I am asking is that I am curious as to the whether there really is much of an audible difference between various sub $500 or $1,000 DAC's, and I haven't come across any DB tests of DAC's. I have read many subjective reviews that claim differences are quite noticeable. Of course, there are major differences in terms of the types and number of inputs and outputs that a DAC may have, whether they include a headphone amp, how portable they are, etc.

I am not trying to start a fight/flame war, I am just curious as to what the 'prevailing wisdom is' on this site. If you think there are differences in sub $500/$1000 DAC's, what do you believe are the relevant factors (e.g., USB vs Toslink/Coax)? I know that 'speakers' make a difference, but am unsure about how much, if any, difference there is between DAC's. Again, just trying to become an informed consumer (and save $), not trying to start fights.

TIA

PS...I should note that I appreciate people like NwAvGuy and others who try to provide quality products, diy options, etc., at reasonable prices.

[pdq]

I'm curious why you felt the need to limit the discussion to sub $500 or $1000 DACs? Is it because you feel that a DAC which costs much more than this WILL sound better in an ABX test?