Hello,
I didn't have a battery problem before the update, and there doesn't seem to be a change after it, one way or another.
I've never seen a battery drain issue on any of my iPhones, my wife's, or any of my clients at work - the only time I hear about them is here on these forums.
If people are having battery issues, it will most likely be games, or some other such thing. I'd try a reset, shut the phone completely off - not just put it to sleep, and see if that makes a difference.
The only trouble I have ever actually seen with the iPhone, and its performance, is when people do a lot of gaming, movies, videos, etc, and even that is rare in my circle of people. Even then, the battery isn't an issue - the battery gives what is advertised.
I don't do games, movies, videos, or music, so maybe that's why I don't seem to have issues like so may seem to.
My iPhone is a near perfect business device for me - I'd hate to be without it.
Cheers,
M.
*****