After using each of these three monitors for several weeks, I would love an amalgam of the three that is built around the Philips adaptable stand, the AOC's power-saving abilities and the Dell's bright screen.
That said, the PowerSensor feature on the Philips 271S4LPYEB is impressive and works well, but it uses too much electricity to be of much use.
I love that the AOC E2752VH doesn't use a watt when it's asleep. At $240, it is also the cheapest to get and use, but that's not enough compensation for having the least bright monitor of the three.
The Dell UltraSharp 27 UZ2715H may not have the fastest display panel, but it is fine for business work and is the best equipped and brightest of the three -- and uses a reasonable amount of power. I wish that the stand were more adaptable, but no other screen here does so much.
3 power-sipping monitiors: Specifications