I have the D7.2s and I bought them for their midrange. To me, vocals and instruments sound wonderful, and music that is subtle sounds as engaging as tracks with more tempo and energy. I listen to a huge range of music genres, and most sound superb. I would say for rock they aren’t natural performers, but do a good job that I can enjoy when I fancy it. These speakers don’t have huge slam and punch, but they still deliver electronic music very well, just again they don’t excel your big dynamic drum and bass tracks.
For 90% of my listening then they deliver perfectly, and the main reason is they are so balanced and do not shout at you, so I can listen to them for hours on end without fatigue.
My partnering equipment is a Hegel H390 which is a smooth amp, and I use the internal dac with an Auralic G2.1 streamer. Never has the midrange been shouty or unnatural, I would say I tested them also with the Michi X3 and did find it edgy and less natural, so I’m wondering if your other gear is creating that.
As for run in, they loosened up over a few months, but really just smoothed out even more than they already were.
Overall an incredibly easy speaker to listen to for hours on hours, I would have assumed they’d be extremely similar to the D9.2s in that regard.