I'm planning on buying an iPhone 6 as soon as it comes out, and based on all the leaks, it seems like the back will be almost entirely anodized aluminum (save for the narrow plastic strips and the camera lens, which I'm assuming will be covered in sapphire glass.) How scratch-prone do you think the aluminum back will be, let's say if I were to keep the phone in my pocket along with my keys? Would using a case essentially be necessary if I don't want the aluminum to get scratched, or will the aluminum somehow be able to withstand a little abuse without showing it?