Well just a little info for future xb1 purchasers when you get bf4 on xb1 the only thing from 360 that gets transferred is gamer score I don't think you get to keep any unlocks or rank. I believe you have to start from scratch
Keep your teammates close and your Dog Tags closer or I will STEAL your TAGS
I read on their forum that you ranks and unlocks transfer with you...was why I bought bf4 for the 360 rather than wait.