I was wondering if anyone has exchanged their T-Mobile Contract-Free Unlocked 6/6+ for the Sim-Free version? I was able to do the exchange flawlessly at Apple today. The first store I went to sold the only single Sim Free Gold 64GB version once I arrived. Luckily, upon suggestion of the Apple guy, he suggested to secure the purchase online and pick it up it-store at another nearby Apple Store, which I did. I was told by both stores that the Sim-Free is better of the two because of the additional bands. How do these additional bands benefit me? Would these extra bands benefit me internationally?