I'm probably going to return my iPad Pro M4 11. I received it on Wednesday moved everything over and it is . .fine. I was coming from an M1 11 iPad and while I can tell a difference, it's probably not worth $1000.
Everything is faster but outside of a few apps, they were already fast enough. The only app that has me tempted to stay is Roon which I use extensively and it was always slow on my M1. It flies on the M4, a substantive improvement that is easily 5 to 8x faster. However, other things are faster (Safari, WSJ, NY Times, etc) but as I said they were already fast.
As far as the display goes it is nicer. Not 10x nicer but nicer.