… in terms of draining the battery. My iPhone 4S used to last about 24 hours before needing a charge. After the iOS 7 upgrade it lasts from 8 am until about 4 pm.
This reminds me of first-generation Android phones.
Separately, the photography interface on iOS 7 seems to have gotten better for sharing photos. After taking a picture from the Camera app you can touch it and then share it. On the previous versions it was necessary to back out into the “Photos” app before sharing. For taking pictures, however, the interface is worse. There are on-screen controls for the flash, HDR, etc. that make it hard to compose the image (by obscuring the virtual viewfinder). I can’t see any way to hide these controls and look mostly at the image to be captured.