ultralite mk5

Hey forum. I've just got myself the MOTU Ultralite mk5. Big part of deciding on this was I wanted something with digital output. It's connected to my Neuman KH 150s via the S/PDIF out. There's one thing that's annoying me though - on the front of the unit there's a hardware volume control...

I am looking to decide what suits me better with this two audio interfaces. A comparative to know in what parts each of them are better than the other. I don't care about what software or plugins that comes with each is better or the compatibility of the drivers, just the technical audio stuff...