I have a MacBook Air on my desk plugged into a Apple 27-inch 5k Studio Display next to my work MacBook Pro plugged into a cheap AOC 27-inch 4k display via HDMI and frankly there's not much difference.
The speakers and mic in the Apple display are nice, but if you're just concerned about the display itself save yourself the bucks and stay with the 4k.
The speakers and mic in the Apple display are nice, but if you're just concerned about the display itself save yourself the bucks and stay with the 4k.