any suggestions on what to replace Bluesound Node 2i with

Innuos Zen mkIII or Zenith mkIII. That is the upgrade I did last year. I went from a Node 2i to a Zen mkIII. The Node is a great piece for its price range, but the Innuos Zen is in a whole different class. I loved it so much that last week I sold my Zen and went to a Zenith. Watch John Darko's review of the Zen. 

I did the upgrade last year and went from a Node 2i running into the Chord Qutest and I replaced the Node 2i with an Innuos Zen mkIII going into the same Qutest via USB. Streaming Qobuz. To those doubting you can't hear a difference in streamers, I am sorry to say there was a big difference going through the Zen. Bigger soundstage, both depth and width, dynamics had more body, less digital glare and harshness on female vocals. The Innuos just has a greater sense of realism, you can hear deeper into the music. The Innuos products are amazing streamers, not to mention their server ability to easily rip CD's to the internal library is insanely quick and easy. They just released their new 2.0 which for me will replace Roon. But there absolutely was a difference and it was far from subtle.