I'm on my 3rd one on my P7P. They can have a different feel depending on what skin you get. I wanted the Triple Black which came free when ordering any Damuscus(still does as of today). So I got the Obsidian and put that on first. Didn't like it, felt like electrical tape. So eventually put the Triple Black on which I did like. After a repair caused a new back glass I now have a Black Carbon which has a bit of a texture that I like. Cases seem to fit over them but tend to pull up the corners if your not careful taking them off. I bought a cheap $5 clear case that's flexy and a bit loose to use when I want a case on.
In case anyone's wondering, I had asked them which skins have a texture and they said this:
The texture of the Damascus Triple Black material is unique in that it follows the design of the material. Deadquarters (and all other Robot City skins) are smooth to the touch, while Swarm, Camo, and Carbon skins are textured throughout the entire skin material.