Ok i'm currently on Att with my 6 plus and planning on switching with tmobile SOON. 1. I don't have to surrender the 6+ right inorder to get tmobile to pay for ETF right? 2. If i do the switch.. will i be able to unlock the att phone and then use it to tmobile? this way i don't have to purchase and wait for 6 weeks because tmobile have the plus on backorder. 3. what's the difference between the att and tmobile iphones? is there any network or spectrum that the tmobile iphone has that the att doesn't? 4. if you throttle at tmobile, is it 4g, 3g, or edge?