any suggestions on what to replace Bluesound Node 2i with

op needs to be more precise... is he replacing the node 2i being used as streamer and dac (e.g. using its analog rca outputs) or is he seeking just a streamer upgrade only...

case 1 makes sense, maybe get a better outboard dac put it downstream of the node

case 2 may be $ spent with limited sq upgrade

The title said I am replacing the Bluesound so I am looking for a replacement, not a DAC. I will use to stream Qobuz
My dealer suggests either Lumin T2 or Lumin D2
I can spend the money on the Lumin T2 but I was looking for other options before buying. I already gotten a lot of good suggestions to check out 

If the issue is sound quality and not other user functionality then suggest trying an external USB  dac with the Bluesoimd streamer for comparison before dropping $4500 on a new streamer/dac.

@mapman +1 My bluesound streams via an excellent analysis plus cable to an R2R tubed dac with various upgrades and a good quality powercord. I would like to A/B the Bluesound with another streamer, but I suspect it would be hard to tell a difference.

But, OP, you asked for opinions about Lumin and I'll confess to not having experience, there. Whichever streamer you do get, if you get a chance to compare it with your Bluesound -- keeping the DAC the same -- I'd love to hear from you what kind of improvement you hear when every other variable (including the room) does not change.

Personally I have not heard significant differences between streamers to same DAC with CD res sources. . Never heard a bad one. Interface type used can matter. Asynchronous USB is the way to go with most modern DACs. I only use wireless internet connections to isolate the streamer from any noise that might exist on a wired connection and find that works great though some claim a good wired internet connection is better at least in some cases perhaps with hi res sources where wireless bandwidth perhaps could come into play.