The Audient units are good - people here and elsewhere that seem to know their stuff speak well of the quality. They were part of that first generation "premium" units, prosumer or whatever you want to call them. I've got the TASCAM US-7000, and it is an excellent-sounding unit. Great preamps (I love my transformer-based pres but these work well) and excellent conversion. Bang for buck they are great, even if they cost twice as much - but they are only $400.
No MIDI and the latency can be higher than RME, but the drivers are steady and TASCAM has their own driver coders these days and put out updates regular-like, which is good.
I've been using the new TASCAM 20x20, and it sounds just about as good. No problems working with it, so if I didn't have the money I'd be OK with using one of their cheaper units - the 4X4 or whatever it is called. The A x B series (not the 7000) all use the same components and drivers and are very high quality.
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