it is also super rare and hails from Germany. These are collectors items more than anything else, but i am sure someone out there uses it as their daily driver. I think 7-Bits avatar on Deskthority is one of these blue bastards.
Also the trackball is alluring for some input fetish folks. But take that with a grain of salt cause i see skidata boards go for hundreds of dollars without the trackball.
I use the one I bought from Ivan
2 as my work keyboard. Sheer intimidation factor alone makes it my preferred choice.

I've got most of a Wyse set on it now, as I bought it sans keycaps.
Not sure if it came stock this way, but it has Cherry MX Whites in the main key area, MX Blues for number pad, and MX Clears for the LED keys. MX Whites are rapidly becoming my favorite Cherry switches.

Edit: The trackball works under Windows 7, too.