Between the 2, I prefer the bass on the MDR-Z1R; it has equally good texture and layering, but it sounds bolder with a touch more potency, resulting in a grander, more involving presentation. For my genre of choice, EDM, the MDR-Z1R provides a stronger kick in the lows. The Sony has a timbre that is lusher and more fluid-sounding; as a result, vocals retain a level of gravitas and authority.
With that being said, the AH-D9200 beats the MDR-Z1R in overall balance and treble performance. It is also easier to distinguish micro-detail, dynamic changes and nuances on the Denon flagship.
It's a toss up between the 2, IMO. If you're going from one to the other, in the overall balance of things, I'd say that the consequence is more of an eventual side-grade than an outright upgrade. Nevertheless, if you're a fan of a cleaner, leaner sound, with good balance from top to bottom, whilst retaining an
excellent bass section, the AH-D9200 can be viewed as an endgame.
I have
compared the 2 headphones here.