Should I buy iPad air 64 gb or iPad air 2 16 gb?

Thank you. I think that's going to be my problem with 16gb, moving files a lot of times. I don't mind the processors, really. I don't even notice it. For me as long as it is working. I was just wondering what's new in iPad air 2 other than touch ID and faster processor. And like you said nothing really that big of a difference.

So thanks!:)