I placed my order for the AT&T Mini hoping I would be able to go the no-contract route or opt into a shared plan with my iPhone 5. Those with shared plans - how does it work? Do I just tell AT&T that I want x amount of data for my Mini and 5? I believe with shared the lowest is 5GB/mo, which is plenty. Am I also charged a shared plan fee on top if the added data? Is shared data advisable or am I better off paying the $30/mo for non-contract? Thanks.