While the AG493UCX does indeed have five buttons to navigate the OSD, AOC wisely decided that using such a method on a screen this large is somewhat ungainly, so the vast majority of the time you will want to use the included remote control. This makes navigating the OSD very simple, with each screen telling you exactly how to go forward and back, and of course select your desired setting, as you are going through them.
It also has dedicated buttons for the brightness and speaker volume, as well as input select and direct access to AOC's game mode presets.
The OSD itself is split into six sections – Game Setting, Luminance, Image Setup, Color Setup, Extra, and OSD Setup:
I can't really fault how AOC has done this. All the key settings are easily accessible, and if you're like me, the thing you'd want to change most is the brightness, which can be done directly from the remote without entering the OSD itself. There's also a handful of gamer-centric features like an on-screen crosshair and shadow control to brighten dark areas. My only initial gripe was that the OSD itself is positioned right against the right edge of the screen, which on a 49in panel, does require a fair bit of neck movement – but thankfully the OSD position is adjustable.
In sum, the OSD gets the job done quickly and without fuss, so I really can't complain at all.