N10 better cable: USB or coax

[ctzzzz]

Hi there
New owner of a N10 here, wondering what do you guys use as digital cable to your DACs.
Do you prefer USB or SPDIF interface?
Of course using USB the DAC's clock takes control and on coax the N10's clock steps into action.
If you also can name your cable brand of choice, that would be very interesting.
I for myself compared an Ultra USB from Transparent vs a (borrowed, unknown brand) coaxial. The results are mixed on my side, to be honest, that's why I want some advise from your experience.
I use an Accuphase DC37, don't know which clock is more refined, Accu's vs N10's.
Cheers, thanks in advance.