Mine just turned up!
Important stuff first:
My Cardas Golden Reference and Nordost Red Dawn interconnects don't fit, at all, which is very annoying. I've got an ancient pair of Audioquest Diamond 2 which do, but they aren't long enough so some rearranging is required.
My Audioquest Vodka Toslink cable doesn't fit either, also because of the recessed inputs.
Holding down the Crossfeed button on switch-on bypasses the volume control, but does so for both line level AND headphone outputs.
Ergonomics:
None of the buttons or inputs are labelled.
Source selection, crossfeed mode and battery life all use internal LEDs to indicate status. I can't see any of the LEDs with it on a my hi-fi rack so I'm flying blind.
The power switch is impossible to use with my thumb, but a small finger with a fingernail can just get it. I haven't tried changing source yet.
Software installation was painless on Win8.1 and I'm using WASAPI at the moment. It installed ASIO automatically, but I've not tried that.
Look and feel:
It's tiny, and weighs almost nothing.
If I hadn't been told it was made out of aluminium I'd have assumed it was plastic (but if I have to carry it anywhere I won't be complaining).
The buttons are small and plastic, including the volume control.
It goes loud. I currently have HD800s, Westone 4r and some cheap Sennheiser IEMs helping run it in, with the IEMs playing pretty loud, the HD800s quietly and the volume LED at light red / pink. I'll want to be very careful with the volume on IEMs.
Stuff I already knew:
The lights are pretty but pure style over function. I guess I'll learn them eventually, if I pick it up and peer inside.
The headphone outputs are on the same end as the RCAs and the opposite end to the input select button, which may make sense for a portable device but doesn't really work on a rack.
Sound:
I'm only 30 minutes in, if that, and running on mains power but it's making my music sound interesting, which is score 1 for the DAC. I'll leave it playing for the next fortnight before making any judgements, but will have to remove the IEMs if I want to crank the HD800s.
I may find I change the way I use my hi-fi with this, moving it around and just plugging it in to headphones or amplifiers according to what I'm doing. I've got a 3m Audioquest Cinnamon USB cable on order which will give me that flexibility. If it actually fits!
Update: changing inputs is a lot easier than switching it on, so that button is fine. I still have to guess what source I'm listening to from the content and the bit rate light though.