Very beneficial in my opinion is the material:
The Hard Case has left on my 3gs then unsightly marks on the display because hard particles had settled between sleeve and display.
The pure silicone skins like me also not because the phone turns then difficult to pull out of their pockets because the material "sticks"
The material of this casing is a cross between hard case and silicone skin. It protects the phone from damage and the material adheres and does not stick.
All 2 - 3 days I get the phone out of the case and remove the dust which inevitably accumulates, but that one has in each envelope.
Can recommend it to everyone the product.