The edge is (obviously) slightly higher than the display height over it. So of course the protection is guaranteed, but it is also catches dust. In Chrome thus also succeeds the Tab switch by a swipe gesture from the edge to the center is not always. But that's not a problem of this envelope, but rather a question of principle or for another Silicone Case.
The buttons can be easily operated (volume even almost better than no cover), the connections are easily accessible.
Why the upper left corner remains free and therefore unprotected, is beyond me.