I don't see anything to suggest it's not the same panel as in the PG279Q (the M270Q008). I don't know what the 'Z' denotes, as on the surface it seems identical in every way. Unless it's just a new revision, but if so I don't know what they've revised. Unless they've done something to combat the bleed/glow which this panel is pretty notorious for. I believe some of the other 27" 165Hz IPS G-Sync monitors (AOC etc.) used slightly revised versions of this panel, so that might be all this is. The specs on those were all pretty much identical, nothing to separate them, but the Asus always seemed to be worst for bleed/glow.