Well guys & gals, here it goes: I am in the USA. I am looking to purchase a Nokia Lumia 1520, 32GB, 2MB RAM "International Version" phone from a reputable on-line retailer in Hong Kong. Their notes for the phone states that it is "unlocked" for all international carriers that operate on GSM. But it is my understanding, that AT&T (my service provider) operates with the LTE Protocol. The "USA Version" clearly states that the electronics do support LTE, but I am leery of purchasing the "International Version", if it does not work with LTE, hence slowing down the phone's calling performance, incompatibility issues, etc, etc. Can ANYONE OUT THERE clear up this matter for me? I have read COUNTLESS posts, but still have no clear answer. Many who have bought the "International Version" from Hong Kong, are in the EU or other countries and have reported excellent service and compatibility with the phone, but I HAVE YET to find a post from anyone in the USA that can claim that "ALL-SYSTEMS-ARE-INDEED-GO" when trying to use this "International Version" with AT&T. Please help, thank you!!!