I would add RME ADI2 to the list. I had this and the Chord Quest. They are both great for the price but quite different. Ended up feeding the RME right into my power amp. After much switching, it just sounded better - fuller bass, plenty of detail (though Chord beats it there) etc etc. I think you have to listen for yourself.
The RME has a graphic equalizer and volume control, and a good clock if you are using USB.