Just to share my experience here. I have achieved 100+ hours and gave the D7200 proper burning. The sound really opened up and improved.
I have been listening to lot of high quality .flac music, all kinds of different genres and also enjoying them while watching movies and little bit of gaming.
Based on my ears and quite a lot of tweaking / experimenting, I have improved the EQ settings a bit further (version 2 attached).
This is just a slight improvement which I believe suits most of the genres out there and mainly it makes these headphones sound really good, amazing IMO.
The aim is to get them as close as possible to the D9200.
I have not experienced with different cables and pads yet but in this thread there is a ton of info about this... not sure why its not about EQ as that can improve the sound significantly !!
As written few posts up here, the EQ used is the Equalizer APO software with PEACE user interface plugin. Both are free to download.
I have tried lot of music with proper / harsh like highs to see if this EQ setting would be also suitable. To my ears this is set to the edge where the highs are really nice, airy and crisp without being too harsh, fatiguing or pierce sounding like.
Anyway, please try them, tweak them, improve them and do not forget to share it. See if you turn these settings ON / OFF how much difference that makes.
Do not forget to burn these in properly (min 100 hours) and EQ them before you consider selling them or getting a refund.
By the way anybody experience any ringing with these yet?