Personally I'd love to see a Schiit SYS-like ABX comparator, i.e. a double-blind listening test switcher, which would help people test DACs by themselves without the usual accusations of bias/sited testing/non-verbal cues/etc. Automatic level matching within 0.1 dB would be an incredibly useful feature.
I know Mike Moffat home-brewed a similar device in the 1970's and found it useful, but something like this would be just as useful today. Especially with the "objectivist"/"subjectivist" craze swirling around, this would allow people to bring forth home-grown but reliable evidence much simpler than getting yourself tested in crazy-expensive studio under the X-ray eyes of the local "objectivist" sceptic.
Software ABX is cheap and widely available, but hardware ABX is tougher to find. With all the running controversy of "a DAC is a DAC" or "R2R vs DS", I suspect there is demand for inexpensive random switcher from just about anyone involved in these terapixel debates. People who do reviews and like to compare gear would probably love to have one handy, too. But just about anyone who wants to test audio gear, including cables, would find such a switchbox useful.
The current market for good, inexpensive ABX devices seems non-existent. The
QSC ABX comparator is no longer in production, while the
AVA ABX comparator sells at 1000$ a pop, which is in ridiculous-pricing land. I find it hard to believe that the cost of the components in the AVA ABX comes anywhere close to the cost of the tech inside a Gungnir DAC... Added ABX functionality and level-matching might justify the cost of making a SYS-like switchbox in a bigger chassis (Bifrost size) and with more input options than just 2.
PS As an example, look at all the hoops one must go through just to set up something resembling double-blind ABX testing at home, for the mundane task of comparing Modi & Mani vs Bifrost & Asgard:
http://www.head-fi.org/t/643368/schiit-modi-and-magni-comparison-to-bifrost-and-asgard
"The Blind A/B Test
I had my wife help me with this, our methodology was as follows:
She would pick a song from my test tracks and play it on one of the two stacks (unplugging and plugging in the headphones each time regardless of whether she switched them on me). She then would switch (or not) the stack that it was plugged in to four or five times, playing the same section of music each time. I recorded which I thought I was hearing and she kept track of what she had it hooked up to. I was in the same room but facing away, and the amps were volume matched using pink noise and a sound recorder I have that has a decibel indicator."
