I have a Bluesound Node 2i. I first did a LPS upgrade on it, which brought about more detail, was a bit more relaxed, more refinement on the top end, and more bass definition. I then upgraded to a SMSL VMV D1SE. Brought about more detail, and again a bit more refinement. Surprisingly the DAC upgrade after the LPS upgrade wasn't as big as I was hoping, but each step for me was about the same in terms of upgrade. But the LPS upgrade was certainly much cheaper.
The Bluesound Node 2i has a slightly warmer presentation stock than any of the upgrades I did.
If you like the Bluesound Node, I would first look at a LPS upgrade, as this will help you down the road, whether you use the internal DAC, or decide on an external one. Will improve the sound to either DAC.
Hope this helps