any suggestions on what to replace Bluesound Node 2i with

@Mahler123 I should do an A/B test of Apple Music 24/44 vs  Bluesound Node 2i while listening to Qobuz 24/192 with my teenage daughter. It could be a hearing issue but I doubt it. My system now is outstanding, it will be even better when I do the upgrades on my equipment

At Deer Creek Audio, we think a lot about the importance of simplifying the digital transmission path. In this case of evaluating streamers, we recommend a solution that includes Dirac LIve room correction. This really simplifies the layout and optimizes the path to your final digital to analog conversion.

The miniDSP SHD series combines the Volumio streaming application and Dirac Live in a high definition DSP and DAC platform.

Adding Dirac to the mix is a game changer because of the way Dirac improves not only the system and room frequency response but also the time domain impulse response. The result is superior definition that rivals the sound you would have experienced in the recording studio.

Dirac, when combined with a high definition streamer, may likely be the biggest improvement you’ll experience in your journey as an audiophile.

Here are a couple of independent reviews, one on the miniDSP SHD series in Audio Science Review, and another on Dirac Live from Stereophile.

$4200 for a streamer! To heck with that. $4200 would by a hot turntable/tonearm combo. You’ve got your priorities mixed up. Turn to vinyl for real music. IMHO. 

This biggest improvement in my opinion is getting a QUALITY DAC the DAC in the Node and Node 2i are fine for well lo-fi listening.

The new Node (no longer called 2i) has a better DAC that the 2i but it is still lacking.

I use a Mytek brooklyn bridge(version 1) and love it. It is a roon endpoint and sound is great.  I believe they just released the second edition which is still under your budget($3500) or you could find a version 1 used possibly for less.  Nice thing here is, it is a streamer and a great dac so you can run the bluesound through the dac and do some a/b comparing with the internal streamer of the mytek and use the winner?  I have compared to streaming through usb (through the Mytek)and the mytek streamer via roon always wins(ethernet)
I bought an astron rm-12 power supply for mine and it really helped the sound.
Highly recommended.