since my (third) Asus Xonar Essence One is exhibiting weird problems too, I'm now starting to look for an alternative.
I'd love to like the XEO but the imbalanced, low resolution volume control and too high output for headphones as well as broken ASIO drivers aren't that fun. It also sometimes refuses to play certain frequencies until I switch between the inputs several times (eg. I hear no voices until I cycle the inputs at least once). This doesn't raise my confidence in the unit. Also, strangely, I find it lacking in bass lately (could be related to my frequency problem).
Therefore I'm now looking for alternatives.
I'd like to be able to drive headphones (low to high impedance) as well as my amp (via RCA). Asynchronous data transfer is something I'd like to have, non-upsampling behaviour (ie. no resampling of 44.1kHz to 192kHz) is a must-have. The DAC should work with ASIO as well as WASAPI on a Windows 7 x64 machine via USB. Sample and bitrates of up to 192/24 should be supported, must be supported up to 96/24.
TOSLINK support would be greatly appreciated (PCM, for the PS3).
My budget is roughly around the price of the ASUS (~420€) but I might be tempted to spend "a bit" more (ideally below 1000€), if I get a DAC that [b]actually works[/b].
I'm looking forward to your suggestions.