My 64gb iPad 3 is still on 6.1.2. I have the notification that 6.1.3 is ready to be installed, but I've never installed it. I'm planning on selling it when the next iPad comes out, so should I just leave it at 6.1.2 because someone else might find extra value in that, or should I just upgrade to 6.1.3 and then to 7 before I sell it? Or does it not matter because when I reset it to factory condition it won't remain a 6.1.2 anyway?