So, I just got a new SIM from AT&T. It's the LTE one. My sister has the iPad 1 and she has the unlimited data account. I have already swapped my AT&T iPad 3 for my current VZW iPad 3. So, I was wondering if I could put the new SIM in the iPad 1 and "activate" it and then take it out put it in my new iPad and put back my sister's unlimited SIM back in the iPad 1 without any problems? I still have an account with AT&T, I didn't choose to delete and it's still active for 30 days. Or, can I just insert it in my new iPad and would it work after I go to view my account and log in? And after, I can take it out and put back my VZW SIM without any problems? This is of course assuming that AT&T SIM works in a VZW model, which seems to have been proven.