Display
This is the big one, quite literally. I’ve seen a lot of people assume the X will be an unambiguous slam dunk in this regard, saying the device has a bigger screen than the iPhone 8 Plus in a body close to the size of the regular iPhone 8. But this isn’t really true, and I think a lot of people used to the Plus-sized iPhones will be disappointed with the X in practice.
Yes, the iPhone X has a 5.8-inch screen compared to the iPhone 8 Plus’ 5.5-inch display. It’s also true that the X’s is higher resolution. But the 8 Plus’ screen is actually bigger. The X uses a narrower aspect ratio, so while it’s longer on the diagonal, you still get more surface area on the Plus overall — and that’s before you account for the notch and the rounded corners. I know, comparing screen sizes isn't what it used to be