The PG279QZ is an Amazon exclusive.
It is the same panel.
It does have a slight redesign. The height adjustment is a bit taller and the bezel is ever so slightly larger, assuming an attempt to reduce bleed as most bleed is caused by pressure of the mounting.
Also the packaging has been changed to not have any graphics on the box, no drivers CD, and no foil marketing sticker on the monitor. These were done to lower the production cost. (i.e. it costs less as well)
This model should have a less chance of bleed because of the bezel change but still would have the same amount of chance for dead pixels, uniformity/brightness variances because its the same panel.
A friend of mine that owns a shop purchased 6 PG279Q(s) and 6 PG279QZ(s) from Amazon warehouse deals,
He did this to test somethings that Rtings tested. He concluded the reason that Rtings tested a brightness variance was because panels in general come in with different max white point brightness.
This is not exclusive to these monitors but also others he had tested. Many of the PG279Q (not Z model) tested a max whitepoint brightness of well over the rated 350 nits but a few also tested much lower at around 330 nits.
Across all the PG279Q and the PG279QZ samples the brightness varied and does not seem to be constrained to the older models or the Z model.
TL : DR
The PG279QZ has the same panel and the same PCB / firmware of the PG279QZ. (Chances of dead pixels & response time remains the same)
The PG279QZ has the same characteristics (brightness etc) as the PG279Q because its the same panel.
The PG279QZ has a slightly larger bezel. (assuming this helps bleed as it reduces pressure on the edges)
The PG279QZ is only available from Amazon.com
Didnt know it was the same panel. Probably all the reject panels that didnt make the cut for the pg279q, hence the lower price & brightness & quality & more bleed etc. despite taking preventative measures against it
My A in the Asus nameplate has fallen off the front of my monitor but no white spots.. yet anyway.
I would not take the risk, I think you and I were of the few lucky ones to get a decent panel. Asus should be ashamed of themselves.