A 27" display is gigantic for 4K at computer monitor distance, the pixels are going to be as big as Christmas hams. Just set it to 100% where it’s supposed to be and maybe invest in a pair of peepers if that’s somehow not easy for you to see. Users under 90 should be fine, though.
I like the 27" size. They’re both 60 hz unfortunately :/ I’m thinking of either one of those really long monitors or two with high refresh rate. I need at least 90 hz. I freaking love 4k and can never have anything else.