have draftsmen with large 4k monitors and they seem to like it just fine. I prefer 3x 24" 1080p just for work organization and making it easier to resize windows quickly. Ideally, I'd make one of those monitors 4k though, but I'm too cheap.
Again, this is for my 4k video encoding machine (it's essentially a tool) that does gaming on the side (because of it's speed), if I was building a more casual machine, I would re-think my layout and a single large monitor might actually be significantly cleaner.