Only Drawback....
The only drawback, and its not much of one, is if you do the above method of putting the car in neutral or leaving it in anything but park and pressing the start button and you have the door locks set to unlock in park (with power off) the doors will not unlock once you shift to park and and go through the restart stop.
Engine on to ACC (on a 2014 AT): Don't put the car into 'park' before pressing the button to turn the engine off. The engine seems to stop, but the accessories are still working. Then put the car into park after the engine is off.
The only drawback, and its not much of one, is if you do the above method of putting the car in neutral or leaving it in anything but park and pressing the start button and you have the door locks set to unlock in park (with power off) the doors will not unlock once you shift to park and and go through the restart stop.