Compared to that pink one, mine is clearly from a different manufacturer.
Mine has a matte finish and is slightly sparkly. The logos and text looks like it was sprayed on (albeit very tough as I've tried to scratch it)
As for the aluminium ones, I've got a silver one on order from another seller on eBay as it looks rather nice. I was hoping the place I get all my parts from would sell these but they've told me that they have no current plans to do so. Fortunate for me though, they do sell diffusers as they sell the OEM black/white back covers.
I might pickup a couple diffusers and fit them to these cases.