I had my DAC 2 upgraded to the DSD option (not SE) as soon as it was available last spring for the same reason queried.
I had previously compared USB input into the DAC 2 from a Windows 7 laptop to S/PIDF input from a Marantz SA8003. I found the sound with input from the Marantz to be a bit cleaner sounding. This was done using identical music ripped to the laptop. It was apparent that the USB converter wasn't as good as it could be and I had considered add on converters, but wanted to stay with the one box DAC, power supply etc.
After the upgrade the sound using the USB improved significantly and I think it now sounds better (smoother but no loss of detail) than using the Marantz as a transport. And comparing using ripped hybrid SACDs, the ripped 44.1 files played back through USB to the DAC 2 seem comparable to SACDs played through the SA8003.
I'm happy with the upgrade.
I had previously compared USB input into the DAC 2 from a Windows 7 laptop to S/PIDF input from a Marantz SA8003. I found the sound with input from the Marantz to be a bit cleaner sounding. This was done using identical music ripped to the laptop. It was apparent that the USB converter wasn't as good as it could be and I had considered add on converters, but wanted to stay with the one box DAC, power supply etc.
After the upgrade the sound using the USB improved significantly and I think it now sounds better (smoother but no loss of detail) than using the Marantz as a transport. And comparing using ripped hybrid SACDs, the ripped 44.1 files played back through USB to the DAC 2 seem comparable to SACDs played through the SA8003.
I'm happy with the upgrade.