Partial collection of my Pures.
Edit: 1 more. + mini comparison
I am quite happy with my new silver cased Pure. The case quality is better than the black versions as well as the Filco case in the background. It has a much finer satin like finish that looks nice, as well as no dings and gouges on it. You can see 2 gouge marks on the inside and outside edge in front of the LWin key on my black case (there are a couple more, but none this bad). It is gouged before the anodizing because the marks are completely filled with color. Then, there are some minor parallel marks on the bottom. Both of my other ones doesn't have the parallel marks, but the silver one's finish is still better.
Silver one seems to have a newer firmware revision than my other Pures. The old one has inversely powered Fn lock indicator. If LED is set to high brightness, then the FN indicator will be dim, and vice versa. New ones only lights up when Fn lock mode is on.
^edited due to fuzz memory and never using the LEDs.