There, while gushing about the iPhone X's Dolby Vision HDR display coverage, almost infinite contrast, and high brightness, Apple slips a few warnings about the inevitable downsides of having an OLED panel. "If you look at an OLED display off-angle, you might notice slight shifts in color and hue. This is a characteristic of OLED and is normal behavior," says Apple. Indeed, as you can see in the GIF image on the right, the screen turns slightly blue at an angle, and it is visible even with the light reflections from the Apple Store chandeliers.
There you have it, straight from Apple's mouth - OLEDs are still not up to par with the orthodox LCD screens in certain areas, yet they excel in many other, arguably more important characteristics like contrast ratio, malleability and cinematic color gamut presentation.