I may upgrade to the mdr z1r soon
I'm considering the same. I just got the Z7M2, but I like it so much that I'm always thinking that I should have gone for the Z1R in the first place. Well, at least now I know what I'll be getting when I do. With a move coming up, I don't want to expand my collection too much at the moment.
For me, the Z7M2 is the first headphone where the term "musical" came up naturally as the word I would use to describe its sound. For the longest time, I didn't really understand that term, and thought it was sort of fluffy BS audiophile jargon, but after I got over my initial reaction to the Z7 and its somewhat unorthodox tuning, "musical" just popped into my head intuitively. I had a realization where at first, I was baffled at what the Z7 wasn't reproducing, like all of the air and perceptive detail seemed to be missing from the sound, but after a while, I realized that everything I was hearing was part of music, not just the byproduct of an instrument. Like the trailing reverb of a cymbal isn't actually part of the music per se, it's not written down in the sheet music or consciously produced by the musician, that reverb is a side-effect of cymbal playing. The Z7M2 isn't lacking in detail at the note level, a cymbal hit is still reproduced and audible, but it doesn't linger or focus on that reverb.
Most of my other headphones are neutral-bright, and they draw my attention to the character and texture of the instruments. "Hear how crisply the decay of the cymbal is rendered!" "Hear the pluck and follow the twang of the guitar as it fades after each note!" The other headphones cleanly separate and emphasize the character of each instrument, while the Z7M2 only presents the character enough to tell me that a particular instrument played a certain note at a certain point in the song. And because it doesn't emphasize the characteristics of each instrument, I find it easier to focus on other elements of the music, like background singers or harmonies, stuff that's written in the sheet music and not just the product of the performance and its recording. It's something that I had to readjust my brain and my expectations to understand, but it was quite informative and eye-opening (or ear-opening?) when I did.
I haven't even messed with EQ in earnest yet. I'm usually a big EQer, and I don't just run parametric EQ but dynamic EQ via VST plugins in my music player. I'll need to go back through this thread to find the EQ settings that cdacosta posted. I didn't find the oratory1990 preset to be a general improvement. A different, more neutral flavor, sure, but it didn't improve the musicality of the Z7M2.