Do I need a new DAC/streamer. Considering?

Do you like the Node2i? The user interface and the connections suit your needs? If so just keep using it, if you have an itch to try something else the Lumin U1 mini or Bel Canto estream are choices you could return if they aren't to your liking. I've tried about 8 streamers as far as sound quality there isn't a dimes worth of difference using them connected to the same DAC. I ended up with the Lumin U1 mini not because it sounds any better but I like the user interface and it had the AES3 connection I needed. 

While I cannot explain why djones51 has not experienced favorable results, many of us have.  The streamer is likely as important and impactful as the DAC - a result supported by direct experience.  I can imagine that some systems will see less benefit, but in my own system - the differences in upgrading over the Node 2 (going into an outboard DAC) were clear and favorable.  So, the only way for the OP to know - is to try one in their own system.

The reason is blind listening. You'll be surprised how alike streamers not using internal dacs sound or if you understood digital transfer you really wouldn't be surprised at all. 

There is definitely no need for a DAC in the streaming device and the only question is whether you want a server between your streaming service and your player or you want to go straight to the player.  Streamers bypass the server and you are simply directing Tidal or Qobuz to your player.  This exposes your player to the volatility of the internet. 

If you have a server in place between player and streaming source (Tidal Qobuz) you get a more stable signal as the server brings in the track and then delivers it to the player. 

If you run Tidal or Qobuz through Roon, it undeniably sounds different than if you send it straight to your device.  I have recently tested this with Tidal through Roon to my 2Go/Hugo 2 vs sending the signal straight to the 2Go through Tidal.  I have a Roon Nucleus+ on my network.  The sound is a bit thinner in the midrange and airier in the treble when you go straight to the 2Go.  Far from ideal.  I found it quite different and found the 2Go was inferior when dealing with Tidal directly vs the Roon Nucleus+ handling it first.  I have no DSPs running in Roon.    

My wife, who doesn’t care a lick at all about the gear I’m running and rarely offers a comment, even when asked, said without a prompt “that sounds better”.  Indeed, I spent a lot more upgrading my DAC than my streamer yet I got more sonic improvement from the streamer.  
  
I understand that you likely have more knowledge than I about such things - and I respect that.  I also understand the there should not be differences from data loss or from timing errors with a DAC that rejects jitter well.   I don’t think those are the culprit - and, from what I gather, neither does anybody else.

What i don’t understand is why you proselytize so regularly on an audiophile forum (where we’re all ostensibly looking for better sound) that because you did not enjoy an improvement in your system, it’s not possible anybody else did either.  

Perhaps your digital network is vastly superior to mine such that your noise floor is well below my own, negating any difference.  I can accept that.  Perhaps your DAC is vastly better than mine over SPDIF (Node only outputs TOSLINK and SPDIF).  I can accept that, too.   And, it may well be placebo effect causing some of us to experience an improvement.  But, there are also reasonable explanations as to why many of us experience an improvement that are other than placebo.  

You might notice that I generally suggest to forum participants that they try in their system as I don’t know whether or not they’ll enjoy a benefit. Very, very few things are black and white and I wouldn’t want somebody who enjoys this hobby to be misled by my experience. Or, yours.