I'm not a fan. Large ultra-wide curved screens are fantastic. With large flat screens that are meant to be viewed across the room, you get a distorted image when you sit up close. Your eyes have to focus further away as you look at things closer to the edge of your screen and the viewing angle for that part of the screen is different from the center of the screen. It also requires more effort for your eyes to look up and down rather than left and right. We're hard wired for that horizontal plane. This makes ultrawide screens a really comfortable option.
I almost bought an 8k 55" screen for use as a monitor, but I tested a 55" 4k screen for a week and the flatness is what turned me off to it. I've been using three 32" 4k screens in portrait, arranged in a "curved" config on my desk (2 monitors on each side are mounted at an angle), which I really like. But switching to a large single flat screen was not fun.
For me the holy grail of monitors is a 55" 8k curved screen. Not "ultrawide", I want the full width and height and I want it curved, with full 8k resolution. Maybe someday, but I'm not getting my hopes up too high.
I'm not the guy you asked but I have a similar opinion on flat screens. Personally I'd want spherical. ~15" tall and ~25" wide is about my limit for flat screens, anything beyond that I find that the corners/edges are too distant/distorted. My home setup is multiple independent 27" screens, which I like. My work setup is a single flat ultrawide (34" probably?), and I find myself physically leaning my head/body from side to side when I have two windows open next to each other. I have eye level a few inches from the top of the screen, and the lowest couple inches also seem distant/distorted.
