Advice needed about setting up new iPhone 4s please

[Markyboy]

Hi all, wonder of anyone can help me. I've been lucky enough to get hold of a new iPhone 4s to replace my iPhone 4, which my wife will be having. Also have an iPad 1 which shares the same Apple ID as the iPhone 4. I'm thinking now whether to set up the iPhone 4s as a new phone or restore it from a back up from the iPhone 4? I've heard restoring from a back up could lead to battery problems. Ideally I'd like to restore from a back up and use the same Apple ID so I can share apps bought between devices. If the two iPhones have the same Apple ID will there be any issues with messaging each other? And also will there be a problem using iCloud? The only thing I use iCloud for at the moment is for a wifi back up once a day when it's plugged in.
Many thanks for your help!

 

[bikerboy]

You can use the same ID even if didn't set up from back up, all my family iPhones and iPads share the same Apple ID

 

[Jerome G]

My family also uses the same ID and we can iMessage each other without a problem, from iPhone to iPhone or to an iPod