Just a guess. The Ref 10 series, with its $30K price tag, is directed for an extremely upscale market. Hence, I don't think it's relevant to include the Ref 10 and Ref 5 in the same conversation.
As far as the Ref 5 is concerned, as I said I have no inside clue about what's coming off the line at ARC. But here's my guess. The Ref 5 is a discontinued model, replaced by the Ref 5 SE, which I think was released in late 2011/early 2012. IOW, the Ref 5 SE IS the "Ref 6." Will there be a "real" Ref 6? I think yes. When? Maybe after the Ref 5 SE has run its course, possibly 2015 or so.
Just thinking out loud here about the Ref 10 series, priced at $30K. It's hard to believe that there's much of a market for gear at that price point. But maybe there is when one considers that there's a market for $100K+ Magicos and the like. Personally, even if I could afford to drop the change, I'm not sure I would. I think the bottleneck is the quality of source music.
