Phone to receiver, or streamer?

I'm streaming music from my phone to Marantz 8012 receiver and it sounds great. Just sending via bluetooth, no complaints. 

If I were to purchase something like the Bluenote node 2i and connect via ethernet etc. do you believe the sound quality improvement would justify the $550? 

I'm assuming the DAC in the 2i would be an improvement over the Marantz, but not certain. 

Its very difficult to improve upon the sound quality from a receiver. Particularly when using such a high-resolution source. It is after all digital. Hard to imagine how it could get any better for any amount of money.
As long as you use a music provider like Qobuz, etc. that provides full CD and hi-res audio you should hear a significant improvement over compressed Bluetooth (assuming your speakers are up to the task). You can use the DAC in the Node or use its digital out to your AVR and pick whichever sounds best to you. Of course, if funds will allow, upgrading to a stereo integrated amp will take your music to a much higher level still. Hope this helps.
Your phone has physical limitations on sound quality.  Bluetooth streaming is not the end all.  Bluesound has a 30 day guarantee.  Try for yourself.  They wouldn't do this if they didn't have confidence.
Bluetooth can be pretty good, but yes, the Node2i will sound better.  Whether it justifies $500 only you can answer
Thank you for the responses! Certainly I'd have to try to know for sure. I was curious if anyone else had taken this step etc.