The only thing I'd miss about the MY is the 7-seat feature. I love the fact that you can technically cram two more people in the car on the occasional times when you need to, without needing to drive a giant 7-seat boat. I wish more mid-size electric SUVs did the same.
I sat in the back seat of a model Y with two other adults and it was extremely painful.
That's not surprising. The point isn't to use it to regularly drive tall adults around back there. It's for when your family of four needs to take two of your kids' friends somewhere, that kind of thing. We probably use it once every couple of months, but it's super handy at those times, and folds away out of sight and mind the rest of the time.