AOC recently overhauled its OSD system, offering settings that are split over seven main tabs:
AOC's new OSD system is worlds better than its older menu UI from previous screens we've reviewed – everything is cleanly and clearly laid out, there's plenty of features for gamers, plus a couple of colour space modes too. I do find it very annoying using the 5-way button controls to navigate the menus though, as I frequently turn the screen off by accident, but it is what it is.
AOC does also offer its GMenu software alongside the U27G4R, providing the same controls but for use directly from the desktop, which is a nice addition. It can also be used to update the monitor's firmware, a feature I always like to see included, so credit to AOC there.