Not a user of Mark's Sablon Reserva Elite USB, but over 3 yrs I've upgraded a whole Audience Au24 loom to first Sablon Panatella/Corona loom, and now currently Reservas
The stuff is spectacular
An amazing tonal density and speed, w no seeming obscuring of transparency or highlighting of frequency extremes
Dare I say it, truly neutral, coherent and pretty darn near perfect
Have heard the new data-only USB on the SGM/Dac8, and it brings a stress-free presentation that really competes w analog
Mark Coles truly is the MasterChef
Mark is the only cable builder who owns his own SGM ! IMHO the low noise floor of the SGM puts Mark in a position to have more insight about the key drivers in USB performance