Art, I've got a problem where this monitor will occasionally not wake from standby. The capacitive buttons do not work and a hard computer reset does not wake the monitor. The power plug must be pulled and reinserted. I was able to reproduce it in Linux and Windows using a GTX 960.
After all these years, when has AG coating caused a real issue? Even the roughest IPS coatings were good enough considering the PPI.
It's so down on the list of important factors for a monitor. I'll never understand your fixation with AG.
Backlight aging is a case by case thing.
My CCFL c-PVA monitor is rated for 50K hours and the white point has barely budged an inch over 11K hours.
LED aging is also very dependent on their operating temperature but as for colour shift in different designs, I don't know too much.
Precision and accuracy of the contrast measurements.
Some manufacturers in the past have not necessarily used the full range of the LCD panel. An example would be where the OSD brightness setting clamps the LCD to dim the screen, rather than the backlight.
The main difference between products...
Light bleed, or poor sealing
Precision and accuracy
Programming of the LCD
Ambient light during measurement
Target white point
If I had to estimate the deviation of contrast for panels I would say 5%, which is fine. There are worse problems...
Samsung display, LGD, AUO and CMO produce most monitor panels. BenQ is an AUO brand. LGD is still on top for performance models.
Panels have an integrated backlight and may or may not come with a backlight controller.
The native white point determines the contrast ratio in addition to panel...
It isn't strange to me. I've used a PVA monitor for years. Viewing it from under a metre produces a stereoscopic effect on mid tones. LGD simply won and consequently Samsung Display and AUO followed suit.