Does the 4 infrared sensor make it easier to detect an actual hand wipe....or face. On the 2013 x you have to swipe over the sensor (blocking light and then unblocking). Usually I just tap the phone it senses movement. swipe a piece of paper over the old moto x and active display activates
With the old x it seems to basically detects change of light. Flash a light on and off at the X, you'll notice active display engaging. Or while driving your car different lighting angles make active display turn on. swiping your hand over the phone in the dark doesn't seem to work as well. Perhaps in the new moto x it is improved?