Alienware's 34-Inch QD-OLED Monitor Launches for $1,299

>what the disadvantages are of an OLED display

Burn-In, Colour accuracy over time, Peak Brightness, Cost.

OLED's look better than almost anything, but they start to wear out quickly. If you don't mind replacing an expensive panel every couple years it might be great. If you want to keep it 10 years it needs to be treated carefully or it will look worse than other tech for most of it's life.

One of my OLED panels clearly shows reduced output/color accuracy in areas with r/g/b test screens. The most obvious is 10 minecraft hearts from the HUD on the full-red screen.