Bring back Bryan wade!!
I wanna caravan for me ma
Both appear to be well received, looking at a new phone as my contract has expired. Any advice warmly received. Thanks 

XS - Better specs on the camera - OLED screen - HDR display
XR - Bigger Screen - Larger colour choice - Cheaper
https://www.apple.com/uk/iphone/compare/ gives you a side by side comparison.
If you can try and view them side by side in a store.
I have an XS Max and I haven't regretted the purchase. (Bought outright)