What is positive: - Cover sitting absolutely firm and fit perfectly on the Lumia - The sleeve is hard - that's not a soft cushion or similar - The device (more precisely, back and camera unit) is very well protected, in particular the (at least in my Limua 820) - The color fits extremely well with the purple-Tiles. Is still discreetly, so no flashy or neon or so. Who's therefore a difference like or want to head to the nearest Church, for which the color is perfect. ;-). Note: I have the shell in black and purple, purple and I find now much cooler. Is just a difference.
The Bad: - Power to the envelope too often from or to, can break the material. I have seen friends.
So who is in trouble, this protective cover often to remove (eg due to Navi), the need to consider the well. All others receive a very good protection to a more than fair price.