A 4K monitor with room to spare

Unlike slightly smaller 34-inch curved displays with their 21:9 aspect ratios, 40-inch panels use a standard 16:9. That makes them very tall. This one's almost 20 inches high (sans bezels); a comparably sized 21:9 display would be only about 15.5 inches. For reference, a typical 27-inch 1,920x1,080 monitor is only about 13 inches tall.

AOC attaches the stand at the base of the display rather than the middle, which is more typical. That partly limits the amount you can tilt it. It's not pretty, and the stand has no cable management, but the connectors are easy to see and reach. That's a big plus in my book. But the tinny, echoic speakers fire backward.

There's a nice set of connection options: two HDMI, two DisplayPort and even VGA, plus four USB Type-A. The panel indicated by the outline at the top of the stand comes off to add a VESA mount.

The display has a gentle curvature.

You can display output from up to four sources simultaneously, but because the monitor's so tall that may not be practical for everyone. 

The menu system doesn't feel optimized for the size of the monitor. It looks low resolution and the options have to travel a relatively large distance when you scroll.

I really hate these distracting, nonremovable marketing stickers.

The AOC uses one of my favorite onscreen-display navigation controls, a joystick. 

One of the monitor's more novel features is Bright Frame, which lets you delineate a particular location on the screen by increasing (or decreasing) the brightness relative to the global setting. Unfortunately, it doesn't work in conjunction with multiple inputs. 

The color options are typical of many mainstream displays. AOC's DCB mode is the exception: it boosts memory colors (like blue skies and green grass). Unpleasantly.