the portrait mode being available on the Xr is very nice. That lens is an f1.8, and in photography it's about light. This means that you can use portrait mode in lower light with much better results. I always thought the pixel 2's portrait mode was better than the iphone X's. I wonder if you can also adjust the shutter speed, etc, and the taking of a pic will be instant compared to the slight lag on the current X's portrait mode.
Do users have the option to use portrait mode on the XS with the f1.8 lens as well? I doubt it.
There's also no reason why Apple can not include portrait mode with every single lens camera iphone that can run ios 12 since it's just software based. It might take longer on a 5s, but it could be done.
Another big reason to go with the XR is because while everyone says the X's screen is the same size as an 8 plus screen, it's actually considerably narrower. By area it's 10% less than the plus' screen, but functionally it still feels a bit constrained. I felt the plus screen was definitely larger still in daily use because it's wider. The XR now has a screen width that is at least that of the 8 plus and much longer. This XR phone is a pocketable plus size screen and I think the final optimization that maximizes screen size for one-handed use. The XS and the previous plus were just too big for anyone to use one-handed. If you were hoping for the old iphone 8 plus to shrink, without giving up any screen size width or height, the XR is your phone. The X behaves like the iphone 8, whereas the XR I think will behave like a plus phone with its landscape mode extras, two panel views, etc.