That's a neat E7 case, MichalTUR, never saw that before. I had my E7 in a simple custom-cut leather-sleeve by fitBAG. I do use a foldable book-case style with my current phone and the main advantages to me are slip-protection and an easy way to prop it up at an angle. The Pro would not need the latter :D
I guess a book-case for the Pro would make more sense with the fold on the right hand side of the screen. That way, you could snap the screen open and it would flip back the cover more or less automatically.