I am in the USA at the moment and have been given a Samsung Galaxy S7 Edge by my brother. The phone is used and is currently on AT&T. I have read all over the internet that phones can be region-unlocked by placing a 5 minute phone call from withing the country of purchase on the network...
Set for official release in February 2016, here's what is to be expected;
The S7 is said to pack a 3,000 mAh battery and the S7 Edge, a 3,600 mAh battery, an increase of 450 and 1,000 mAh, respectively. Removable batteries remain off the table, however.