$1300-1500 DAC

Another vote for Audio Mirror Tubadour.

@andrewkelley
Have you compared the Simaudio Moon 280D with any good 1.5k DAC?
I believe a good dedicated DAC with a good source should sound better. If not, the Simaudio Moon 280D is a giant killer as, for the price, its a streamer and a DAC.
If not, may be you should think about upgrading your main system with a better streamer + DAC and keep the Simaudio Moon 280D in your second system. It would cost a little more, but you could get better sound in your main system, as I guess could be better. Of course, you would have to change the Bluesound Note for a better sounding bridge like the SOtM SMS-200 Ultra Neo or the cheaper Sonore Ultrarendu. 
I prefered my SOtM SMS-200 Ultra Neo + Gustard U16 USB Converter + Audio-gd R8 Ladder DAC combo (about 3.5k total) against a +20k Mark Levinson streamer and DAC and also vs a +20K T+A DAC.
Just an opinion. 

I have just done exactly what you are thinking. I had bought a Chord 2qute Dac which was too bright in my system, I have swapped this out for an Exposure Dac which has a very organic analogue sound could not be happier. It is a brand which is often over looked. 

I really like my audio mirror tubadour lll, it's very musical. Can't have it all at $1500 but it's certainly not going to be shamed by a more expensive unit. 

I think that I’m just now finding out that the node 2i will ONLY OUTPUT 24/96 over coax! What kind of crap is that? The whole reason I bought the thing is for a streamer, and to use and external DAC with it. Urgggghhh