I usually use it at either 2560x1440 on one of my two primary desktop monitors, or 2560x1600 at my game table laptop. But I also frequently drag it over to my tertiary or quaternary screens (or secondary laptop screen) which only supports 1920x1080 but I could easily live with less visible functional on those smaller screens.
I am also running it in an embedded browser component in my main campaign management software, but that only steals about 150 pixles or so.