I currently have an iPad Mini 2 on AT&T. Im planning to switch data over to Sprint. I was going to purchase a new iPad Mini 2 for Sprint. However, after looking at the specs, it appears all the iPad Mini 2,s are the same? Its just the SIM card that differentiates them? Is that correct? If so, can I just get a Sprint SIM card and put it in this iPad Mini 2? Thanks!