I went from X to 13 Pro. I plan to get a 15 Pro in the spring.
I checked and found that I used the telephoto lens enough that I'd likely miss it with a non-pro phone. It's as simple as that for me. I honestly don't notice much difference with pro motion myself - if I could set it to 60 Hz always if it saved battery I'd be just fine.
One thing that bugs me about the 13 Pro vs the plain 13 is the weight in my pocket. So knowing that the 15 Pro will be better will be a big plus for me.