I don't care what anybody says, but LED lights "pulse". Some are worse than others, but EVERY led light I've ever seen (car lights, christmas lights, under cabinet lights, etc.) have a horrible flicker to my sensitive eyes.
Trust me....I know that more expensive/better made led's exist, but the all are based on a pulse modulation system, IICR. Heck, even dimmers in your house light work on pulsing, but traditional arc lamps don't INSTANTLY turn on and off with these pulses, and led's do. Even if it's extremely fast, I see it - especially out of the corner of my eye for some reason. I also see flicker on plasma tv's (more out of the corner of my eye again), but notice it straight on as well.
Maybe organic led's are more constant/stay TRULY lit, 100% of the time. I really don't know much about OLED, but that would be a benefit of them right there.