Another issue I can see being a problem with me and an iPad mini is the very narrow bevel when held in portrait. In an attempt to keep the mini narrow they have used a bevel so narrow that there is no way I could hold it the way I do a Kindle or even the iPad3. My thumb would constantly interact with the screen. The only solution would be to cup the mini in my hand, which would not be comfortable or very useful. I admit that I thought Amazon had lost their minds when they increased the width of the Fire HD by giving it a wider bevel. But now that I have one I admit it was a smart design change as my thumb never accidentally interacts with the screen like it did on the original Fire. The ipad3 also has a wide bevel which prevents my thumb from accidentally interacting with the screen.
Currently: Kindle Touch, iPhone 5, and iPad 3.