The D7200 really improve with time. May be the wooden cups and the pads getting settled?
To those who find the mids a bit shouting/ringing, I recommend trying the
Lawton tune-up kit, more exactly the adhesive paper-like disc from it, or something similar, attached to the cups from the inside.
I measured the D7200 in original form, without the Denon polyfill damping, and with the Lawton tune-up disc (only). While measurements (below) are almost identical, the paper damping totally kills the subjective shouting/ringing for me. I need a few days to evaluate it more thoroughly, but this principle seems to work well. None of my selected ringing tracks ring any more than my other headphones.
One could experiment with the other elements of the tune-up kit as well - I have not kept them.
Another thing that made a rather big positive improvement is to take off the (original) pads, fold out the flaps, and carefully cut off the dust-cloth. That thing withholds too much treble/midrange information. If you want another dust grill, use something like the Stax dust grills. This material Denon used is just too thick and dense.
Of course, this destroys your original pads, so do this on replacement pads, or then just assume the risk.
The end result is rather pleasing, this is a fantastic closed headphone.
Red: no cups damping.
Green: original damping.
Blue: with the Lawton tune-up disc.
Not much difference on the other things either: CSD, impulse, distortion are nearly identical, but they do sound slightly different (red ~= green, blue sounds better than the others).