Re: Greasy screen.
I find it annoying enough to keep the seven inch screen of the tablet I use primarily as an e-book reader clean. Just a few swipes is enough to put distracting rainbow streaks in the place my thumb "turns" the page
Now you know why all my portable devices have a matte, oleophobic protective screen. I found I'd ended up with an almost compulsive gesture to wipe especially my phone after a call, and I *know* I have clean ears as I shower daily :).