Sorry for chipping in so late. PC at my Mom's place conked off & I'm typing from my mob.
Firstly about the setup. The B&W floorstanders are too big for the room. Also, the right speaker was placed deep into right corner. The Bass was overpowering to such an extent that not only the midrange got obscured but even the furniture was rattling. Pulling the speakers about 2' into the room & right speaker 1.5' from the side wall did improve things but the rattle was not fully gone. We located the culprit to the attic door on the left top corner. We kept the attic door open 3' & bingo, the rattle was history.
The Oppo sound was disaster of sorts. The bass was bloated, sound stage was narrow & mids were thin & distant. Beresford DAC did improve things but bass was lean & sound stage was still narrow. We replaced it with M1. The sound stage was much better but the bass was tighter but still leaner, comparatively speaking. The highs didn't have the sparkle. We felt that things would improve if the speaker grills were removed. Removing them resulted in a huge improvement. Mids became more bloomy, the sparkle of HF came out beautifully & there was overall improvement in sound stage. So in all fairness, w wanted to hear the Beresford again. Things were better than before but it was apparent that M1 was better. We them introduce the audioD. I have no hesitation in saying that it not only matched the costlier M1 note for note but improved the bass majorly which was taut & impressive. Of course the highs were not as prominent as in M1 but according to me, the AudioD would be more suited to long listening sessions as fatigue would be lesser. Someone wanted to go back & listen to the Oppo once more. Sure enough, the loose bloated bass & narrow sound stage were back. I could not listen to the Arcam as I had to leave.
I feel that we should've experimented more with AudioD; use it's pre amp & bypass that of Rotel & vice-a-versa, trying out different settings, different op amps etc.
IMO the AudioD is far greater VFM than M1.