Earlier in the year I was searching for a monitor that I could use to switch between my work-supplied MacBook 16 and my gaming PC (Nvidia 1080-based). I decided to go with the Acer XV273K (27", 4K, 120Hz).

This monitor has some things that make it a nice thing to share. It has 2 DisplayPorts and 2 HDMI connections for lots of connectivity.

I am currently using the 2 DP connections, one for MacBook, one for PC. The PC runs it a 4K 120Hz just fine and the MacBook is running it at 4K 60Hz. I haven't been able to get the MB to run at higher than 60Hz, unfortunately. I am using a usb-C to DP dongle from BENFEI. Maybe a different cable would help?

I have the Mac set to scale the desktop rez to 5K screen space, which works fine. It is clearly not as hi-rez as a natvie 5K display, but it looks pretty darn good to me. Much better than a 1440p monitor.

I have had not problems at all with this setup and highly recommend it