I have no doubt the laptop streamer would sound better with ddc. I'm just questioning whether the $1800 would be better spent on better streamer. That based on my reasoning that stopping contamination upstream is preferable to downstream.
Hmm, not sure I agree that ddc could be of benefit for any streamer that no. 1 lacks I2S output, that is if we believe I2S is inherently better than any usb. Or no. 2, has I2S output, but not as well implemented as a ddc. You're now seeing streamers with proprietary interfaces, based on reviews I have no doubts those better than typical I2S setups. I'll continue to maintain optimized I2S superior to optimized usb.
Perhaps some of these proprietary interfaces will make it into more affordable equipment, until then we really only have usb and I2S to play with. Not expecting that anytime soon, sure these technologies patented, so reverse engineering would have to be diy thing.