Interesting stuff. I was wondering about the DIR9001, as the limited opportunity I've had to compare both had the DIR9001 give a better result over the 8412. However, if the 8412 can be coaxed to give just as good results in a DAC (I'm thinking along the lines of the Northstar I owned, which was similar) then all well and good. Maybe they've built the equivalent or better for a great price.
A good thing though is the proliferation of interesting DACs between $400 to $1000. When I started, there wasn't a lot available in that price range, at least that was well known.