I noticed that since iOS 7, my iPod Touch needs to hug the wall.
I used my iPod Touch generally as an alarm, listen to the local radio station stream in the morning, and then flip through Flipboard at night before I go to sleep. Pre iOS 7 I could do this over the 5 day work week and only see low battery levels on Friday night.
Since iOS 7, I see the 20% battery warnings every night forcing me to plug-in the iPod Touch. I don't accept that the battery has "worn" out since this is not usually an issue with Li-ion batteries, especially not in the < 2 years I have used the device, and especially not since I updated to iOS 7.
Apple does need to do some aggressive power saving improvements in their iOS software layer, period. I find that iOS 7 nags me way too much with notifications, which I have mostly turned off and noticed a slight improvement in battery life, but overall there is obviously something running in the background draining the battery, even when it is unused most of the day. I don't use an iPhone but I can't imagine the experience is much better given if people use it to actually talk and text on throughout the day.
I think Samsung is being a little facetious as they have a larger battery in the S5, but Samsung and Google seem to be highly focused on improving battery life from software optimization alone, if the new Android L is any indication. Hopefully the same focus will happen with iOS 8, but I find Apple is more willing to trade in battery life for some bell or whistle so I am doubtful it will be a dramatically improved over iOS 7.
In general the whole mobile industry needs to find a new battery technology to get these devices "off the wall" a little bit longer.