iPhone 4S | 5.1.1 to 6.1.2?

Hello,

I have iPhone 4S on version 5.1.1 works great so far, I have decided not to upgrade to iOS 6.

My patience diminishing by the day and I want to update to iOS 6 to enjoy his improvements.

the way im using my iPhone:

3G turned on only when needed

Brightness - about 40%

Use a lot in WiFi when there is in the environment

not playing games much

Sends most SMS/What'sapp Instead of talking on the phone...

I read some users had significantly and less significant battery life and it is quite a matter of luck it's battery after update to iOS6.

What do you recommend??? I do not want to rush to upgrade but it's time I think.