A few thoughts for those with "heavy" drain.
1. Will the 5.0.1 upgrade cause everything to be re-synched if you are using the cloud? This might be a reason for the initial battery life drain which some are seeing. Hundreds of contacts, hundreds of emails, lots of documents, etc. may take some time and will definitely drain the battery a lot. Wi-Fi sync will drain slightly less, 3G sync will drain more. Maybe some of you need to relax a bit and see if the issue is still there after a few days and maybe a few full battery charges. I have not reviewed how fast it will sync but if you are synching 1-2 GB on 3G, it could take up to a few hours and will definitely suck a lot of battery.
2. Might still be a few Cloud sync bugs remaining. I have had my 4s since day 1 and over the first few days, the battery was discharging very quickly and one time the phone did get rather warm. I was using the cloud for some things but not everything. I later limited cloud services completely (except FindMyPhone) and the battery has been quite decent since.
3. Cloud sync is a nice feature but for those who are happy synching when you drop it in the cradle connected to your Mac or PC, than I would suggest turning the cloud service off or maybe limiting to "find my phone" which is a cool feature to have available but I am perfectly happy with cradle sync.
4. Cloud sync is great if you must have updated stuff every single minute of every day. If not, you are wasting battery life and not gaining anything.
5. I think Apple is having issues with the accuracy of the battery meter, which is likely a software issue and not a hardware issue. Much like the issue they had on the iPhone 4 when the signal strength meter was over-estimating the number of bars. Many 4s owners have said they have a lot of actual time remaining when the battery meter indicates 10%; much more than using a standard logarithmic measurement of % drain per hour.
6. Limit your battery use by customizing some of the features. I noticed significant improvement when I shut off “Siri pick up to talk” and a few of the other settings (particularly time zone adjust if you are not traveling all the time) which have been discussed in great detail. But definitely review your apps and their use of Location Services. Push email, multiple email accounts all using push, etc. will drain a battery rather quickly. Be intelligent on the features you really need and the battery life will be very acceptable and maybe get better as Apple finds any remaining bugs.
7. It is possible some of the 4s models may not have had the battery optimized well before they left the factory. Doing some full charges after the phone is allowed to fully run out of battery have proven to improve the battery life significantly. It got better with each full charge for me over the first week. The 99 cent Battery Doctor app might be useful for a while till Apple finds remaining bugs. I installed it a week ago and it seems to have helped.
8. Apple has published battery drain estimates for all forms of use before the phone was out. In reading many of these posts over two weeks, it appears some people do not yet have a grasp on this info. Many people seem confused about the numbers. You will not get 200 hours of standby and use the phone for 8 hours on email, talking, surfing, playing music, etc. Everyone uses the phone differently and there are a million variables.
Folks – please relax a bit. Apple will do the right thing. Give them a little time and be patient.
DD