I was going to get a Z1R for a second location from my Ed8. Most of my "critical" listening is done with my Frankenstein Stax stuff, but sometimes I just would prefer plug 'n play.
However, with Z7 selling for 300 to 400ish$ used on ebay, the Z7 appears to be one of the best current headphone bargain "close-to-high endish" type stuff, and the described sound signature is exactly what I am interested in.
I also like the smaller form factor and appearance of the Z7 over the Z1R. It's nice to know the "echo chamber" empty plastic backing can be scotched a bit with surgical tape of all things. I have messed with headphones before, and I believe that the surgical tape stuff can work. I think the felt piece in front of the diaphragm is probably there to prevent the helmholtz beaming tendency so I will defer that, but who knows?
I don't know how much the Z1R magnesium dome contributes, because it looks like it is spliced onto the rather large LPR-Al surround, whereas the Z7 diaphragm is a single piece of LPR-Al.