When I was first thinking of these I was very tempted by the upgraded ones for the spring reverb and the sake of it, but as I look further the blue doesn't look right to me and the gray is less nice than the black and also seemingly perpetually out of stock (even moreso than the regular), so I'll probably just end up with a standard (if I decide to get them when they come to the US).
I'm also intrigued by how Thomann has the blue one listed for only $17 more than the black and resultingly ends up coming in cheaper than any US dealer, even after the $50 shipping. I don't understand how they work.