I have tried both in my home. A friend who is a Chord fan thought the Dac64 would sound better than my D1. It didn't. I still have my D1 and have yet to find a better DAC in my auditions. That is not to say a Boulder or some newer unit won't best it, but there are none of these around Chicago to demo against my D1.
I have tried many besides the Chord that are in the $6k and down range. That seems to be the price limit of what is kept in stock for dealer demos.
If you have a D1 and a transport with AT&T or AES/EBU, the D1 is really very difficult to beat. For Coax or Toslink it is still a top performer among other top performers.
Discontinued, or not, I would hold on to your D1 until some big evolutions in Dacs comes along. They'll come eventually.
Best Regards,
