Ray Soneira, the display expert behind DisplayMate, posted a piece on test results of Samsung's latest Quantum Dot TVs in real world ambient light. He found that Quantum Dots can help boost a display's power efficiency by 75% by maintaining color accuracy in bright ambient light with lower brightness:

"Since ambient light washes out the on-screen colors, the first step is to enlarge the Native Color Gamut of the display as much as possible. Quantum Dots, which is the technology used in the Samsung 65Q9 TV, can now further expand the Native Color Gamut very efficiently ...

A major advantage for using this advanced technology rather than the current brute force method of just increasing the Picture Brightness in ambient light is that it can produce the same vibrant on-screen colors in ambient light with 75 percent less display power up through 2,000 lux, which is very important for TV energy efficiency, and also very important for Smartphones because they depend on limited battery power."