I’m really surprised there are so many who say no difference at all. My experience says otherwise. And yes, I have DACs which reject jitter well.
My journey started with a fully optimized and dedicated Mac mini for serving music only. I then bought an Aurender N100H. It also outputs to my DAC via USB. Very noticeable difference in sound between the two. I then tried using an outboard USB to S/PDIF converter on the Mini - which helped, but the Aurender was still much better.
I bought a Node 2 for a kitchen system and out of curiosity compared it (as a streamer only) to the Aurender. The latter sounded much better.
I took my Aurender to an audio shop where I’m friends with the sales team and manager - and it’s the shop where I bought the Nodes (2 of them actually as I gave another one to one of my kids). That dealer was interested in bringing on a line of better streamers. We directly compared the Aurender, a Lumin U1 mini (about the same price as the N100H) and the Node 2 - all going into a Marantz reference player/DAC. The sales guys and I all agreed separately that the Aurender and Lumin U1 mini were close but the Aurender was best. The Node 2i - as a streamer only, was not close.
I more recently bought another streamer/server - moving upstream from the Aurender N100H - an Auralic Aries G2. I did a comparison between the two (because I could have returned it). Was it night and day such as listening to a true high performance system vs a budget system? No, but the new unit is absolutely, unequivocally, and unmistakably better sounding than the Node 2i and it’s also better sounding than the Aurender. The differences are primarily revealed as spatial information - more openness and clarity - that information that helps us listen more to music and less to boxes. In fact, the difference between the Auralic Aries G2 and the Node 2 (as streamer only), was greater than the difference I found when I very recently replaced my DAC with one 5x the cost.
Though some posters make me wonder, I assume these forums are generally populated by audiophiles - people who enjoy listening to music and who seek ways in which to better the experience through system development.
Some of us have modest systems and seek highest value. From that framework, I would suggest the Node 2i might be the pinnacle. I still have mine in that kitchen system. However, for those here are looking for higher performance, it’s readily available, but like in most things, it’s costly to get there.
Peace to all this holiday season - however you may celebrate.