ASUS ProArt PQ22UC Professional Monitor , 4K (3840x2160), OLED, 99% DCI-P3, HDR, Smart detachable Stand

I got the Asus ProArt PQ22UC 21.6" monitor from Amazon Wearhouse Deals in 'Like New' condition. Its default contrast setting is 80/100. The monitor is power limited, so when you take a white word page and blow it up to full screen, it decreases brightness, to keep power consumption low. This is why Linus Sebastian's review reported accurate δE at a small screen portion and poor δE full screen. But do not trust misleading reviews. Linus isn't as bright as his monitors. Reduce contrast to 50/100 or lower, and this issues is gone. After calibration in lower contrast, I measure an average δE less than 1.0. This is exquisite accuracy.Until you move the colorimeter to a different part of the screen. The Asus OLED suffers from uniformity issues. 50% gray looks patchy. 100% white shows shades of pink or red. This can happen with consumer OLED TVs, but not what is expected for a $4K monitor. We are being charged $1 per pixel to beta test premature inkjet printed OLED technology. Not acceptable. My 2014 Sony PVM A250 OLED is perfectly uniform.On the plus side, this display is very accurate at low brighness/contrast and discerns shades or gray very well. This was very important to me. Much more accurate than the Sony PVM A250 OLED (which crushes shades of gray at low brighness, they all look black). Some people, like Linus Sebastian, enjoy bright monitors, but I don't fancy a torch shining into my eyes. I prefer to work at a comforable low brightness, while keeping high accuracy. This monitor looks at a photograph, perfectly accurate without too much light hitting your retina. It can easily distinguish between all shades of gray, unlike my Sony PVM OLED. I can thus use the Asus OLED at much lower brightness and work much more comfortably. With the Sony, I have to increase brightness too much to discern different shades of gray, which makes it tiring and uncomfortable to use. This is why I prefer the Asus OLED over my Sony PVM 250 OLED, despite the uniformity issues of the former.Finally, 4K @ 60Hz is hard to push for all Intel GPUs. You will need a computer or laptop with a discrete, modern AMD or Nvidia GPU. Otherwise you will see 4K @ 30Hz, which is horrible, or you will have to reduce resolution. Unfortunately, lower resolutions look horrible in this monitor. It would have been better if Asus made this monitor at 1080p native resolution. You do not see 4K pixels at 21.5", so anything beyond 1080p is useless.UPDATE: I received a replacement. Same uniformity issues. Seems a problem with OLED technology. LG OLED TVs have it too. The replacement is seriously defective. (Every minute or so, it displays a message 'power saving' and dims the screen. A minute or two later, the screen goes black, while I am writing this review, or watching a youtube video. The replacement went straight back.) I will not gamble with Amazon Warehouse Deals any further.I ultimately decided to keep the original monitor as the uniformity issues do not bother me much. I really enjoy the accuracy of this monitor at low brightness. Its lack of backlight makes it really comfortable to use. My visual cortex is relieved and for me this is worth the price tag.