A premium product that is tailored for the PRS300. The brown grained leather looks as good as the photo suggests, with a light grey velvety/felt interior. Finishing and stitching is immaculate, and the whole feel of the case with the reader inside is of holding an old leather bound book. There's no creaking, stiffness or tendency to close in on itself in any way - it's just nice, comfortable and usuable right out of the packaging, and certainly protects the reader much better than the neoprene case it comes with.
The mount is a solid one piece flexible ended resin spine, where the two prongs are gently eased open to then snap into the two holes on the left side of your reader. I guess they could break given enough force, but that really would be user roughness - plenty strong and secure for it's purpose in general use. It's so neatly designed, I can't see any real need to ever remove it from the case in normal reading use - except for occasional cleaning.
One thing that should be made clear (just for useful information) is that the brown version doesn't have the side clasp that the blue one has in the photos. I don't see it being a problem (I'm guessing it would be more of a hinderance than a help anyway, covering over the screen when open).