Should I stay with iOS 6 on my iPhone 4S or update?

I do like the looks better on iOS 7 but it drains my battery so fast.

I suggest update to iOS 7. Most of the apps and games in AppStore requires iOS 7. Updating to iOS 7 is like having a new device.

There are various settings that come with the iOS7 that will allow you to minimise battery drainage. I have been using it since the launch and it is of course better than the iOS 6 in all sorts of ways. I recommend you to upgrade and you will feel the difference for yourself. Here is a link with detailed comparison between the 2 operating systems; http://www.v3.co.uk/v3-uk/review/2295962/ios-7-vs-ios-6-head-to-head-review. Hope that helps and have fun!

It may drain the battery faster but apps are being optimised for IOS 7 and soon IOS 8. So they will stop coding for IOS 6 meaning your apps will no longer be updated, so any bugs and crashes won't get fixed. I'm guessing IOS 8 battery life will be better, hoping they learned from IOS 7.