Not sure if it’s the case this year but last year and I believe in most years there is an actual difference in the LTE bands supported by the different versions for each carrier. Verizon one was superior to AT&T one for the X, but the SIM-free is always the version with the most compatibility worldwide (and is in some cases equivalent to one of the carriers’ models).
Anyone know of the differences this year for the XR and XS, if any?