I've seen numerous threads about this, and I thought I'd add my voice.
Contrary to popular belief engineers do see these forums...
Anyways, since I upgraded my VZW iPhone 5 to iOS 6.1 my battery is draining continusouly.
For example today it dropped 12%(100% to 88%) sitting in my pocket after some light texting, maybe 5 to 8 messages, and one app update.
LTE radio was disabled, and it was on WiFi, access point is right next to my desk.
Here is what i've done:
Reset all settings
Perform iTunes restore
Perform iTunes restore with iPhone in DFU mode
Reset all settings again
All the battery saving tips were in place, brightness around 35%.
Barely getting three hours of usage, and 12 hours of stand by.
My iPhone was fine before this.
Being a software engineeringish kind of a guy at a college that Apple recruits CS and CE majors from, I feel like I have a decent understanding of my phone, so I don't feel like my perception is a PEBKAC problem...