The built-in streamer inside Meitner MA3 is actually quite good. Unless you're going for high-dollar streamers (think > $10K), you would be hard pressed to find an improvement. I recently bought an MA3 and took it to a friend's house who has also recently purchased Aurender N200. We didn't notice any difference in SQ using MA3 by itself or hooking up to Aurender. I sold both my streamers -- Aavik S-280 (one of the best I've owned thus far), and Innuos Zenith MK3. I plan to use MA3's streamer until I'm able to afford more expensive streamers (> $10K retail).
In my system, the MA3 is fantastic! Very balanced, natural, zero digititus, and a truly three-dimensional soundstage. The focus here is on creating a natural sound vs. hyper-realism.