This is a huge issue and very dramatic on my phone. I bought the iPhone 5S (my first iPhone) on November 13, 2013, installed some apps, wi-fi, bluetooth etc. and the battery drain was what I'd call normal (not much drain during the day). Nothing noticable. I update to 7.0.4 on Saturday morning November 16, 2013) and right away I notice that the battery is draining as i'm using the phone - 5% in 15 minutes (and no different usage then before the update and no new apps either). I'm replacing the phone to get back to iOS 7.0.3!!! This is ridiculous - where's the field testing??? Yes, I already restored the phone to factory conditions once - same battery drainage issue! Way too much time spent on this already. Very disappointed.
Tom