I use AN and LED on my N5 and they aren't even close to the same thing. The LED blinks a color at me at a certain speed when I've, say, been texted, called or emailed from someone I've preset (a relative who has health issues for example). The AN comes on too, but the AN goes out after a moment. The LED keeps blinking away. If I've wandered away from my phone for a few minutes and then return, I can see if there's something that needs my immediate attention, without thinking about needing to touch -- or even being within arm's reach of -- my phone.