The mark of a great device is that it should just become sort of boring. A tool. One that is reliable. One that you just grab and use when you need it to perform the tasks for which it is built, and that you then put down satisfied that you have it even if you are no longer OMGing every time.
I think this just about sums up my iPad. I think it explains part of the reasoning behind me looking at and investigating Chromebooks in the last few days, in that the Chromebook is new and shiny and the iPad is now "boring".