I went from iPhone 11 Pro to 13 pro and I can tell a slight difference in weight but not much. The two things that I am finding I need to get use to are the flat sides and the camera bump. I prefer the rounded sides of the 11 pro. The camera bump is just giant. I am trying to learn to put my hands in different places because I find myself touching the bottom part of the camera a lot.
100% this^
Any difference in weight is not noticeable, but "blind pick up" of the phone and knowing the orientation is going to take some getting used to.
My pinky finger is programed(while not looking) to find the open bottom of the Apple Leather case and then knowing how to hold or pickup the phone so top is up and bottom is down. I noticed yesterday picking the 13 Pro up off the passenger seat while at a drive-through, the 100% edge coverage of the Apple Leather case made me pick it up completely upside-down.
No more PinkyProTouch TM
It will have to be that MASSIVE camera bump that helps identify the orientation that will then of course be covered in finger prints. All minor problems.