Different sets of iPhone X owners are complaining about a couple of issues that have cropped up with their AMOLED displays. One group is complaining about their screens becoming unresponsive in cold conditions while some others are complaining of a green line marring their display.
https://www.notebookcheck.net/Some-iPhone-Xs-suffering-from-screen-freezing-others-green-lines.263580.0.html
There are absolutely no issues with OLED display on Microsoft Lumia 650 and 950/XL devices. Everytime some says iPhone X is the best one I have to laugh ::)