Snapdragon 801 does really well in "real world" battery life. Maybe that's why every high end device on the planet outside of a few Samsung phones and Apple's iPhone use it.
A friend of mine was complaining that she had to recharge her iPhone 5, after 5 hrs of usage(viewing the net, playing basic games) and that kind of poor energy efficiency/endurance is largely why I haven't even been tempted to get a smartphone yet.
Would love to see if Intel through design & process superiority, could quadruple the endurance of these phones(not sure how much is SoC & how much is screen), as that is something I would certainly value very much.