I've had my DAC1 USB since shortly after it debuted in 2007. I bought it after both Peter Aczel of The Audio Critic and Siegfried Linkwitz both gushed about its measurements and power output to the headphone amp. It was a chunk at $1,200, but it was better on the budget than something like a maxed-out headroom DAC at the time (AND for like $2,300).
I will never give it up. I have a cheaper JDS Labs Element at work, which blends in well enough in the office. There's just something about the DAC1.