I am reading this thread for a couple of days as I am trying to find great warm closed headphones with punchy/colourful lows, realistic mids and smooth/softer highs. The comments here and the 70mm drivers were promising. I found a demo Z7 and gave them a try, so I'll add some thoughts for those in doubt.
I never really considered Sony, but lately they have made up their mind about strategy and decided to focus on higher quality products (generally, not just audio). They cut a lot of unprofitable lower product lines and did a very good job with some newer ones, so I really believed in Z7.
I am still not sure if the pads are leather or pleather. Sony website says "luxurious leather earpads", but this thread
says it's pleather. Whatever they are, they get a bit too hot too soon. I don't think Z7 pads are easily replaceable, so this might be an issue for some people, myself included.
They sound best with thick tracks like
Mogwai - San Pedro. You won't hear the pulling of each bass string (as with Beyer T1), the lows are not too punchy and clear, but they are layered in a strong flow. A lot has already been said about the highs in this thread, so there is no need to elaborate. They are soft and I liked them.
The mids are the most tricky. I would agree with
@Allanmarcus on "boomy" and "veiled" sound of Z7, which made me cross them off my list. They definitely have
a ton of upper bass and lower mids, and while it adds fun and emotion to thicker tracks, it doesn't go well with quieter and airy ones like
Sufjan Stevens - Only At Christmas Time. The lower guitar and vocal notes sound reverberated and inappropriately hollow. It hurts soundstage and mids reproduction for both voices and instruments.
I usually prefer richer upper bass and lower mids (is there one word for it? I thought it was 'midbass', but i am not sure anymore), even if it means less detail. Today was the first time I wanted this 'veil' to be recessed with Z7.
Z7 definitely works well with most genres for some people - and some genres for most people.
Naim UnitiQute 2 I used for the test is not a headphone amp, and it leaves me with a feeling that I didn't drive Z7s nicely enough, but I compared them to some HPs I am familiar with to make sure of the result.