It's never really been about the devices themselves. It's about getting the end user to look up and pay attention to the safety demo. To see what happens when people ignore the safety demo then go into YouTube and see the "Hudson" evacuation. Count how many life jackets were inflated before the idiot left the cabin for a start. Then count the idiots jumping off a perfectly good floating wing into the icy waters only to get a brainwave and clamber back on.
One minute taken to listen to the safety brief and look around for your nearest exit shouldn't be that hard.