I see your points. However my system is already configured to be fed by 2ch sources, so having additional sources for all the amps isn't a real advantage. It'd be just giving some use to gear that would rest unused. Not much of a point paying for 6 channels I don't need. Pros will use them, but not me. Then there's the pro oriented issue. If the current ULN-2 is pro oriented, I don't see why an improved ULN-2 wouldn't be too.
I'm quite happy with the "main" DAC I've been using for the last 7 years or so, not really into "improving" it. Getting the ULN-2 would be more for the AD capabilities than for the own DAC. However if for a sensible price I can get also an interesting DAC, why not. I might sell the DA-11 -or bringing it to this system- and still having a computer compatible DAC that sounds good. Like the DA11, I'd only use it for computer as a source duties, playing HR files, not for the CDs I have at home.