It always amazes how differently people perceive sound. I have read on this forum that someone had sold his Marantz HD-DAC1 after he got the Audio GD R2R 11. To his ears the Audio GD sounded more real, music had more body etc.
Since I own both DAC/amps myself I did a comparison. Music used: Mendelssohn's Midsummer Nights Dream / Philippe Herreweghe.
I compared both units connected to my Marantz CD 5000, playing the Mendelssohn CD and after that I connected the Marantz with my iPhone and the Audio GD to my laptop and fed both with Spotify, playing the same Mendelssohn album.
The difference in sound between the Mendelssohn album on CD (coaxial connection) and the album on Spotify (USB) was less apparent than the difference in sound between the Audio GD and the Marantz.
The Marantz beats the Audio GD in almost every possible way: more weight and punch to the sound, better instrument separation, better layering, more 3D, better definition, better texture, bigger dynamics, both micro and macro, more detailed but with a similar smoothness, there is none of that supposed Delta Sigma glare found in this Marantz unit.
In the 1st run the difference was so obvious that I started to doubt myself. The Audio GD lacked bass impact. It turned out that the gain on the Marantz amp was set to medium and the the gain on the Audio GD on low. So I set the gain on the Audio GD at high (it only has two settings. lo and hi) and it made a difference for sure, an overall improvement. I thought that was it, but nope, the Marantz still sounds bigger and more engaging.