John Atkinson's November, 2007 review of the Bel Canto e.One DAC3 is up on the Stereophile site. For the most part this $2,500 DAC looks to be a great edition to a computer based audiophile setup. However, if you are stuck using USB you'll also be stuck with 16 bit / 44.1 KHz. One so-so aspect of this DAC is the fact that it upsamples everything to 192 KHz. I am just not into upsampling and would rather have everything passed through as it came in to the DAC. John Atkinson does compare the DAC3 to the Benchmark DAC1 USB and his reference Mark Levinson 30.6 DAC with some interesting results, but opinion nonetheless.
UPDATE : According to Bel Canto, they are working on a 24/96 capable USB DAC3 and should have an upgrade in late 2007.
"... At the other end of the spectrum, low frequencies didn't have quite the extension or the impact of the Levinson No.30.6, but that's hardly surprising: the long-discontinued Levinson, with its massive separate dual-mono power supply, remains unrivaled in that area, in my experience. But I had to give the nod to the far-less-expensive Bel Canto when it came to midrange and treble purity. There was a sweetness to its presentation that allowed the music to communicate more directly..." John Atkinson, Stereophile. Full Article at Stereophile
Here are links to the user manual and a detailed whitepaper from Bel Canto.