Agree with the other owner thoughts in this thread (clean, clear, dynamic). I listened this morning to the Weiss 501, Igor Levit's Piano Sonata No. 30 (Beethoven), which I just heard Levit play at Carnegie the other week. No stereo is going to match Carnegie acoustics, but in terms of musical engagement, the Weiss is delivering. I agree with the Stereophile review's comment to the effect that it's as if you're looking at a picture that just has more pixels -- that's what's giving you the additional musical detail, not artificially upping the contrast settings on the picture.
Love the small form factor as well -- ergonomics on this are perfect, as I personally don't want a hulking 20+ lb. box for a DAC.