I’ve already did at the Apple Store (I’m Italian and I went to the new Piazza Liberty store in Milan when Tim Cook was there last week

funny experience) ...I tried both and the Max is definitely not for me. I have small hands. But battery is my first concern... I’m not looking for 1,5 days or more, but at least a full day with some juice left.
Looking at battery comparisons the XS should be slightly less then the 7 Plus (at 100% battery health)... so I should be fine... I think? I’ve read mixed things about XD battery life