DisplayMate has concluded that the Samsung Galaxy S20 Ultra's display is "visually indistinguishable from perfect" and has awarded no less than 12 awards to the phone. The publication gave the Galaxy S20 Ultra's display an A+ rating and notes that it has "text book perfect calibration accuracy and performance".
https://www.notebookcheck.net/DisplayMate-awards-the-Best-Smartphone-Display-title-once-again-this-time-to-the-Samsung-Galaxy-S20-Ultra.452497.0.html
Too bad the display has holes in it, eliminates both - the hardware proximity sensor and the LED notification light, and keeps the Always on Display on in the pocket. Technically, it may be "perfect", but practically, it's far from perfect.