Just wondering if there any issues before I go ahead with it... I would like to sell my current iPhone 5. I have a spare iPhone 4s which I will be using instead. My question is...will I get charged for switching from iPhone 5 to 4s (like an activation fee or something else)? Will AT&T make any changes to my legacy unlimited data plan for switching from iPhone 5 to iPhone 4s without asking me? Is there anything else I should be aware of (not technical, limitations of the old phone)? I have a micro sim adaptor that I can use to switch back to the old phone. I appreciate any guidance. Thank you.