well, i have a usb tuner. it's not ati's though, but it's usb.
the limited bandwidth of USB is not as good as that of my aiw radeon
so the image quality is not SUPER. it's good though. i was very satisfied with the image quality. UNTIL i got my aiw =)
i am sure USB 2.0 will mean superior image quality =) but still, it's not "here" yet. =)