Nice update mate, and welcome to head-fi!
I've also found a new review, share with you guys, from Singapore I guess
http://wwenze.blogspot.com/2011/10/asus-xonar-essence-one.html
Verdict
The price of $699 may seem steep compared to the STX, but the chassis, power supply and control circuitry of an external product easily costs a good fraction of a complete product. Add the SPDIF inputs and digital volume control
s, and the Essence One isn't really that expensive compared to the STX, and for the extra money you get a pair of expensive PCM1795 and some form of upsampling, courtesy of the DSP. And lets not forget the Essence One only seems expensive compared to the STX because the STX is super-cheap compared to everything else.
It is hard to give a verdict on something that does not have an alternative for its price. It is very easy to give a verdict when its alternatives are a few times more expensive. The measurements already justify the price, and if you are a believer of measurements and/or ASUS, wants an external DAC and has SGD$700, what are you waiting for. Do consider the STX if you are cash-strapped, but in audio it costs a lot more just for that extra bit of performance, and especially if that performance is the best.