I have the new 9.7 iPad Pro and have an AT&T SIM installed in the SIM slot. It's all working fine, but I'm going to be traveling internationally soon and so want to also select an additional plan with the Apple SIM. I have unlimited data and so I want to be very careful with this. So, when I go into Settings > Cellular, under choose a data plan, it currently says "AT&T SIM Card" and below that it says "Add a New Plan". I have two questions: 1. If I add a new plan, will this just be using the Apple SIM and be an additional plan, i.e., I definitely don't want to replace my current unlimited data plan and so I would only want an additional plan where I could freely move between the plans? 2. Which plan would be best for international usage? T-Mobile has a $10 plan that's good for 5 months, but I assume it's only for the US? While there is a GigSky option, it only allows me to add plans for the US and Puerto Rico (I guess because I'm in the US?).