Question about multiple devices on the same Apple ID
I am currently an iPhone 4S user and have one Apple ID.
I intend to buy the new iPad soon and share the same Apple ID so that I do not need to keep switching accounts. However I have a question.
If I use both devices for iMessage, and if a friend of mine sends me an iMessage, will it appear on both devices? Or just the iPhone/iPad alone?
Also if I backup the data using my iTunes account to the new iPad, will I still use the same iCloud (5GB) or will I be given double (additional 5 on the tablet)?
Thanks.
iPad, iOS 5.1