IMO you can't go wrong with either. I had the Opus 21 and went through the difficult decision recently of having it upgraded with the GNSC mod or purchasing an already statement modded Wadia 860se.
I am thrilled with the Wadia as I'm sure I would have been with the upgraded Opus.
I did get a chance to directly compare the upgraded Opus with the stock Opus and felt the upgraded unit provided some nice improvements...a more organic and solid sound...you could hear deeper into the music with the modded unit.
I never got to directly compare either Opus with the Wadia.
My system has changed significantly around the upgraded Wadia vs the Opus so even memory is of no use.
I am thrilled with the Wadia as I'm sure I would have been with the upgraded Opus.
I did get a chance to directly compare the upgraded Opus with the stock Opus and felt the upgraded unit provided some nice improvements...a more organic and solid sound...you could hear deeper into the music with the modded unit.
I never got to directly compare either Opus with the Wadia.
My system has changed significantly around the upgraded Wadia vs the Opus so even memory is of no use.