Thanks for the A2A. I actually have both (an X and a XS Max).
They are very similar phones with the XS being better at a bunch of things in ways that many people will find minor, or even of zero consequence, but will make a big difference to others.
Most people that already have an X probably have very little reason to get an XS, but to be honest this is frequently true of Apple’s year over year improvements. They aren’t “big enough” for most people until you stack several years worth together.
So off the top of my head:
The X is available in one size, the XS is available in that size and also a “Max” size which is externally the size of the iPhone plus models, but with the tiny bezels that is a whole lot more display. (People that like big phones may find this a big deal, big enough for a one year upgrade…or maybe they just never bought the X in the first place)
The XS’s camera is slightly wider, as in angle of view. It is kind of a small change, but in the camera world people pay more then the iPhone XS’s price to get another mm or two wider field of view.
The XS’s camera is better in low light, for example capturing a poor image where my X captured just a black image. It will also capture a decent image where the X would catch a poor one.
The XS’s camera is way way way way better at capturing pictures with high levels of contrast. Where the X would capture the majority of an image but the highlights would all be white (say where a light source is glaring off a semi-reflictave surface) the XS gets a fair bit of detail.
You can buy an XS with more storage then the X (obviously a big deal if you were “out”, or an option you can avoid paying for if you don’t need it)
The XS’s CPU is faster, also it uses less power
The XS’s GPU is faster
The XS has more RAM (this will actually be surprisingly hard for most people to notice)
The NFC on the XS will under some circumstances work after the iPhone has run out of power (this could be pointless for most people, but if you get a train ride home, or unlock your car or home with it, it could be a huge deal)
The XS’s wireless charging is faster (and as an example of “So?” this is mine, I don’t like to wireless charge phones)
The XS supports duel SIMs, although outside of China one has to be an eSIM so this may be of even more limited use then you would think
The XS is slightly more water/dust resistant
The XS has a longer batter life
Some additional LTE modes/bands are supported, which could be a huge deal If you live/work where they are used, or pointless if you never go anywhere that they are needed
Videos are recorded in stereo…hey, did you realize the last 8 or so years of iPhone video were all mono? Me neither. I sure haven’t noticed the new ones being in stereo either, although I’m sure some will get great value from this feature
Oh, the speakers are louder
I’m sure I minded some other things, but they are all small, except to people that really want that one thing, then not so small.
Seriously I’m not making fun of anyone that really loves the new gold color or whatever. If you can afford it, then it is just a personal choice. (or if you have a legit business reason for your company to buy it for you)