Thank you for making a thread about this I am really interested to read more about it.
Coming in April 2012
I hope it's at least 1.5 times better than the GT40 personally, only because it's bigger and it's almost double the pricier.
Also there is a part at the back of the PCB in my GT40 that was left unused, but it was in place for implementation of S/PDIF like the first prototypes had. The Esprit will have it, but the phono equalizer was traded off for it. So it becomes more of a commoner multi-input DAC+Amp combo, although with a rarer digital preamp the GT40 didn't have, and the ADC coming back. Okay I think it's still fairly multi functional.
The USB DAC on the Esprit (Spirit, in French, but that sebchoq you know it ;-) ) is the same of the GT40. This:
24-bit/96kHz Tenor TE7022L Hi-Q USB Audio Streaming Controller supports ASIO(Audio Stream Input/Output )
Around here you can see empty solder spots,

Prototype #2 (notice how it was rated for 32 to 600 ohm and it became 16 to 300 later... the Esprit will be for 32 to 600 because of that same inscription on the device on images)

And here just next to the USB port there are coaxial and optical digital in (and out).

The Esprit has one more RCA input and one less coaxial digital output.
Here's one year earlier prototype (#1)

One day I'll buy one of these super USB cables, just for the hype.

So many knobs... the GT40 and Esprit only have one to do the same job.

Shiny top, rough cuts, not perfectly flat. Only optical in-/ouput this time. Cool power cable plugging.
Having not bought the GT40 in the first place I would have picked up the Esprit... in the end it all depends of your needs and I will stay with the GT40 for my student years, because of those needs (USB music).
Edited by devouringone3 - 3/10/12 at 3:15pm