I used to use one. At first I thought it was a good thing. But later, when I kept my signal level down in my music mixes, I found that the difference it made was marginal. (don't record tracks close to 0dBFS, it just makes digital sound awful when mixing signals this hot.). PCM sounds remarkably good when used optimally. And, yeah, I have recorded to 24" and mixed to 1/4" all mixed analog, so I know the sound of good analog. I think good analog sounds fantastic. But for music or post? I think it is not enough of a box to make that much difference.
As for film, I don't know anyone using one, and I found it too cumbersome for routing to simply use as a Summing Bus. How best to use it?Map the LR,C, Lfe, Ls, Rs. to the first 6 inputs? Problem there is, it is only a stereo summed output. Put the FX in L&R and the DX in mono 3 and the foley in 5-6 and the BG's in 7-8? What about music? Again, only a stereo device.
i can't think of any independent post house, mixing stage or studio owned TV suite or Dib Stage using one. I think that is telling. Some movies sound pretty good, don't know how the D 2-B would help.
I sold mine.
They make great gear though, and Chris Muth certainly knows how to design. I use the Dangerous M-Q for VU metering, heaphone Cue mixes and talkback.