No real issues at all. The camera is fantastic - the best on any phone ever.
If there was one thing I preferred on my previous 7 Plus, it was the aspect ratio of the screen was better when watching video. With the X either the full screen is not used, or top and bottom are cut off watching video. But I prefer to use my iPad for that purpose anyway, so nothing of concern.
I have no issue with the notch (now rather like), while the Face ID, the new swipe gestures and OLED screen are all definite improvements.