Looking at Brooklyn DAC+ or possibly Supremo

interesting, according to the specs the supremo has discrete analog output, while the Brooklyn uses cheap opamps. As well, I see two transformers in the supreme. However, the ESS chip in the supreme is older (ESS9018) although double.   In short, just looking at the pictures and the specs the Northstar Supremo looks better.  However, that says nothing about sound quality. 

I'd add the Metrum Onyx to your list maybe for a different option.  It's an R2R NOS DAC (I believe the others you're looking at are upsampling DACs), which some consider to have a very natural and organic sound.  It trickles down a good bit of technology from the much more expensive Pavane and reportedly captures a lot of that model's performance capabilities, and price wise it slots right between the Brooklyn DAC and Supremo.  It's relatively new so if you don't see any reviews I know there are some on the Jade, which is the same DAC but offers preamp capabilities as well. 

Also, if I were you, very high on my priority list (maybe even higher than a DAC) would be a preamp upgrade as the RLD-1 in stock form will hinder the capabilities of your excellent amp -- but I'm sure you probably know this.  I had the RLD-1 in my sysrem on demo paired with my DNA-0.5 Rev. A, and in stock form I found the RLD to lack the transparency and detail to run with Steve's upgraded amps.  It's not a bad preamp at all, but like Steve's amps they are initially designed to a price point, and I believe he has upgrades for the RLD-1 that may well be worth looking into.  Although I confess I'm planning on pairing my DNA with a nice tubed preamp in the future.  Anyway, FWIW and best of luck with the DAC. 

Interesting you brought up the preamp.....I was ready to either going to try for a Pass X1 or the P10, or have the RLD-1 upgraded.

Once I found a sweet spot with my IC's, litz chassis wire, and Clarity CMR's....the RLD-1 sounds hauntingly transparent. I'm sure there's room for improvement, but after trying the Intenso DAC, I realized how good a quality stand alone DAC can sound.

I will likely upgrade the preamp next, but I hope I'm not putting the cart in front of the horse by starting with the dac.

I wanted to add another option I was researching, and that's the iFi - Pro iDSD.

Haven't seen many reviews though.

I may even remove the Brooklyn+ from the list and debate the ifi Pro iDSD and the Auralic Vega.