I'm awaiting another sale to buy the 12.9 iPP and while waiting I'm trying to determine which case to buy. I have the Smart Case on my Mini which is perfect but Apple apparently decided to low-ball our case options for their Pro models even though logically they should have the best of all. But I do know I want a Smart Cover at the very least since it's somewhat protective of the screen and thinner than the iPP back cover. I plan on drawing a lot on this though and it will be on a desk/table quite often so I was wondering would simply folding the Smart Cover all the way flat to the back be sufficient enough to protect the back from scratches while on a surface? Or does it pop off easily and/or slide around too much?