This mixer is okay for a setup where you necessarily need a mixer in Volca format. Like, you want to have a rack of four Volca's powered from a single external source.
Otherwise it is overpriced and sounds mediocre overall. For half this price you can get Behringer's or t'bone's mixer with USB audio interface and way more inputs, outputs and controls.
Anyway, even for a studio setup including several Volcas, I'd rather go with mixer from another manufacturer.