My friend Raymond Soneira from DisplayMate wrote an interesting article for the SID Information Display magazine on Tablet displays technologies in real world ambient light. The displays obviously progressively degrades as ambient light is increased, and Raymond then shows how you can compensate and correct images by by dynamically modifying the color gamut and intensity scale.
The article points out the importance of using a managed wide color gamut in displays. Here OLEDs (and also LCDs with Quantum Dots) have an advantage obviously over regular LCDs. This basically means that by having a wider color gamut, a display can be made to look better under ambient light.