Disclaimer: I am not even half way done with Rick's loan.. IOW, I've got a long way ahead! :)
"MDR-Z1000 is meant to be used outside of a recording booth, while MDR-CD900ST is specifically made for musicians residing inside of the booth. ... The sound, of which a musician hears on stage, is basically a cacophony of noise from various sources. Yet, by clearly distinguishing his performance from that of others, a harmony is created. ... On the other hand, a mastering engineer listens to the entire session, and accurately checks the tonal balance of the result."And unlike its sibling, Z1000, which is equipped with a liquid crystal polymer diaphragm, ZX700's diaphragm material is made of a plain PET.
CON: The frequency response follows the diffuse-field reference only from 100 Hz to 3 kHz; IOW the bandwidth is too short to be considered as an ITU standard compliant studio monitor, not to mention the high level of sub-bass distortion is a minus too.