There is some info here and there on it. I think it's a cool item, but the white ink is problematic for clogging heads. The metallic needs to be laminated and the printer is slow as molasses printing metallic.
Go on rolands site and look at the specs for the printer without metallic and then with metallic.
Metallic printing is about a third the speed or less.
Personally I wish I had enough of a demand for it. I would have one machine just for metallic work, but I am in a small town w/ no demand for it.