I've moved from uDac-2 to uDac-3 , and I believe that it worth to upgrade. Here you can see my thoughts:
Now I've got a headphone amp Schiit Magni ($110) and again, I believe there is an improvemente in the headphone amp section. However, I felt much more difference between uDac-2 and uDac-3 than between uDac-3 and Schiit Magni, here you can read my thoughts:
By now, I'm thinking in buying the Schiit Dac Modi, however, I think that the uDac-3 is an excellent DAC and it would be difficult that the Schiit exceeds in quality quality the uDac-3. From the $$$$ point of view : Schiit Magni + Schiit Modi + a decent usb cable + a decent pair of interconnects ... it may easily exceeds the $250, ..., so I really don't know if is is worth of ...
However, thinking in some $250, it may have sense to move to the new Nuforce Icon DAC ($300 at Amazon):
Other option that looks great is the Musical Fidelity V90-HPA, a headphone amp with an asynchronous usb 24bit DAC ($200 at Amazon):
I have an old Musical Fidelity V-Can, and this is excellent, in fact, after breakin Magni for some 40 hours (maybe I'll need more time), the Musical Fidelity sounds with much more bodie, 3-dimensional, more bass, much more power, ..., it is just better than the Schiit (original price was $200)!
Edited by RelayerCR - 9/22/14 at 6:22pm