I started noticing it after I went to iOS 7.0.2 and now that I am at 7.0.3 I definitely notice it. I have gone through the suggested fixes too with no luck. Posting this to see if others are having issues. I know I have read plenty of forum posts with people having the issue, but figured I would post something on my blog about it too.
My iPhone 5 with iOS 7.0.3 will shut down anywhere from 23% down. I did not have this problem prior to just a few weeks ago. My iPhone 5 is exactly a year old. No problems with battery at all until recently. I did notice that when it shuts down early I can usually turn it back on by pressing the top button a few times. In fact, if I go through a sequence of pressing the top button ten times and then pressing and holding it would turn on almost every time. Odd! When the phone would turn back on, the battery level would be at whatever it left off at (i.e. 23% on down).
If after going through the power on sequence it would turn back on, I did try running out the battery by going through this until there was nothing left. Went through batter recalibration and still the same problem. I did notice that if after it powered down if I put the phone in airplane mode, it would not shut down on its own. I could run it all the way down to 1% without any problems. I did close out all programs, turn off wifi, etc, but if it was not in airplane mode it would continue to shut down.
Personally, I believe this is a iOS 7.x.x issue and not a problem with my phone. Especially considering the number of people reporting this problem in Apple discussions and other forums. I sent a tweet to @9to5mac to see if they had these problems reported to them or if they knew anything about the iOS issue causing the problem. So far, nothing back from them, but I am sure thinking it is a issue with the iOS.
I am curious to know if those still running iOS 7.0 are experiencing this problem. What about those running 7.0.2 and then finally 7.0.3? Granted, some of the results might be varied by those having battery issues, but I do not believe the issues I and others are experiencing are batter problems.