Usb3 compliant just means that it "should" run under usb3, which is not always the case. Both specs wouldn't warrant the usb3 performance anyway, 2-3 channels at 48Hz.
I have a focusrite Scarlett 8i6 which is usb3 compliant and runs nicely under usb3. I think the whole range of Scarletts are like that now. It was a choice between the focusrite and the presonus when I got my new laptop, but presonus couldn't guarantee compliance at the time.
It's a bummer that cardbus has died, I loved my emu1616m.

Chris