Hi guys. I have a pretty solid idea of what I want to do and how to do it, when pre-ordering the new iPhone, but I would like a second opinion from a few people. So I am a current AT&T user whose contract expired over a year ago. Since I still have a grandfathered in data plan, I would like to stick with AT&T, but I want to buy an unlocked, because I will be using it for international travel as well. Here's the thing, looking at the options for the iPhone 6 right now, I can choose between full price SIM-less and full price t-mobile, which appears to produce the same results. Full price SIM-less doesn't exist for the 6S. Is it safe to pre-order a t-mobile phone and just stick my AT&T SIM card into it?