Recommendations - DAC $500 w/ USB

Has anyone had any experience w/ the Musical Fidelity V-DAC? ...especially compared to the Cambridge Audio DACMagic? These seem to be two of the obvious choices for those of us who can't/won't drop big money on a DAC and who want a USB input to use with a computer.

Are there any other DACs that should be considered?

PS Audio has a fine unit with USB for 650 used,no problem to resell either.Your a little light at 500,YMMV
Thanks, Usblues! So you're saying that the stretch to $650 will yield a vast improvement in performance? ...especially when compared to the V-DAC and the DACMagic?

If so, I'd be willing to save a little more, but I'd really like to get some feedback from users who have direct experience with all or at least two of the mentioned DACs.

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Consider the Taiwanese units - Valab at $200 shipped, Keces at $275 and various Paradisea units from $350 on up

All offer unbeatable price performance ratios