There was a thread specifically asking for iPhone X display information. Can't find it now, so unfortunately had to create a new one...
Anyway, here's what looks to be an in depth analysis of the screen...
http://www.displaymate.com/iPhoneX_ShootOut_1a.htm#Conclusion
Interesting paragraph from my first glance of the conclusion...
A record high Full Screen Brightness for OLED Smartphones of 634 nits, which improves screen visibility in high Ambient Light. The Samsung Galaxy Note8 can produce up to 1,240 nits, but only for small portions of the screen area (Low Average Picture Levels) – for Full Screen the Note8 can produce up to 423 nits with Manual Brightness and 560 nits with Automatic Brightness only in High Ambient Light. For small portions of the screen area the iPhone X can produce up to 809 nits (Low Average Picture Levels). On its Home Screen the iPhone X produces an impressively bright 726 nits.
Anyway, here's what looks to be an in depth analysis of the screen...
http://www.displaymate.com/iPhoneX_ShootOut_1a.htm#Conclusion
Interesting paragraph from my first glance of the conclusion...
A record high Full Screen Brightness for OLED Smartphones of 634 nits, which improves screen visibility in high Ambient Light. The Samsung Galaxy Note8 can produce up to 1,240 nits, but only for small portions of the screen area (Low Average Picture Levels) – for Full Screen the Note8 can produce up to 423 nits with Manual Brightness and 560 nits with Automatic Brightness only in High Ambient Light. For small portions of the screen area the iPhone X can produce up to 809 nits (Low Average Picture Levels). On its Home Screen the iPhone X produces an impressively bright 726 nits.