For what it's worth: today I had a quick listen to these and the D7200 to see if they might offer something that the 800S does not.
(At home I listen to the 800S with Amir EQ from the 800S review.)
The Denons I listened to without EQ.
First up was the D7200 which was quite underwhelming. The bass seemed good and deep but the halfway from the mids upwards sounded too recessed. One song was enough to lay them aside.
Then the D9200: the sound is very satisfying and quite smooth, not forward or in your face but still very detailed. I was impressed by the open sound of them and did not realize until reading this thread that they are closed backs. This makes it even more impressive.
Compared to the EQ-ed 800S the D9200 seemed a bit more elevated in the bass region. There is some peaking somewhere in the highs which indeed can be a bit harsh sounding in certain songs but it does seem to add livelyness & detail to the sound. This sound feels like the mids do not get as much attention as the rest, maybe you could call it slightly V-shaped.
Both Denons are quite light and very nicely built. The size adjustment mechanism feels robust (all metal) and clicks nicely in the steps you can set. I had to set them just about the largest size to fit my head. Earcups are not very large but fit perfectly.
The cable simply plugs into each earcup and was very easy to switch from one HP to the other.
Nice review. I had similar impressions comparing my D9200 to my Hd800 SDR. My opinion is that both cans benefit from a little eq to specifically target a 1 or 2 treble peaks. Makes a huge difference. My other observation was that the D9200 tolerates a lot of bass eq without audible distortion, whereas the HD800 does not. So you can achieve near-subwoofer bass with the D9200, but not with the Senns. This adds to the overall performance of the Denons.