I'm about to order my WIFi+Cellular ipad (4th gen) and have a couple of questions. The Verizon model: Is it any different from the AT&T model? Is it unlocked? When I travel to say Europe can I pull the SIM (if it has one) and put in prepaid SIM and use Data traffic that way? Could I even use a SIM from another domestic carrier? Can I use tethering? with the $30 plan? And is it truly month to month? The AT&T model: I really dont have many questions on this since i have a grandfatherd iPhone plan with them so I know about the plans and such.... except is it locked to AT&T? and could I use another carriers SIM in Europe or here in the US? Thankful for any answers!