Moving up from a Node 2i

You should be able to snag an Auralic Aries Bridge for a grand.  While the software isn't nearly as good as ROON, Auralic does make both the h/w and the controlling s/w - so it will 'play nice' together. One drawback, however is the fact that the software does require an Apple iPAD for the controller (any version should work) and you can pick up an older one for $100 or so on eBay or Amazon. You can use with a dedicated USB flash drive, USB SSD or a NAS (network attached storage) drive. Not the last word in fidelity, but overall I've been very pleased with my investment.

All, I always wonder about this too - can someone explain how the “delivery mechanism” (my phrase) of the 1s and 0s of a digital signal can make any difference, and to the extent it does, why is that? I also have the node 2i and am tempted to sell it, get a better dac and run a usb from my iPhone and play tidal.  My understanding is that iPhone will unfold mqa. How would this be different than using the node as a streaming source if it just delivers 1 and 0s? I appreciate everyone’s anecdotes but can someone explain the technicalities? 
That said, on another system using a Schiit dac, data from a cd transport seemed to outperform my Tidal phone stream of the same content via USB. I can think of no technical reason for why this should be... but it does leave me with the uncomfortable idea that a “better” streamer - e.g. the AlloOne products - may have merit to the extent they eliminate electrical noise from data delivery. 
Please share your thoughts. 

My thoughts is it has more to do with the hardware and software of the delivery  mechanism. I like my Node2i  to me it sounds good in my system but I know something like a Matrix Element X uses much better hardware from the dac to the controllers for USB and digital inputs. 

Noise ingress and egress and jitter are issues with transports/streamers...

Amir does an excellent job of covering jitter...
https://www.audiosciencereview.com/forum/index.php?threads/digital-audio-jitter-fundamentals.1922/#p

Got started in streaming with a Node2 serving files off my PC. Initially used the Node2’s onboard DAC, but found it lacking when compared to the one in my Resolution Audio Opus 21 CD player. The Opus has a digital-in connection, so I ran the Node2 through it; problem solved. The Node2 made for an inexpensive introduction to streaming and I used it for a couple of years.

Unlike other commentors, IME, Bluesound’s technical support was poor. To be fair, my network setup, in particular the security which is required by my work, is fairly complex and their techs didn’t have the expertise to deal with it. Certainly not the level of support one would expect from a network device company. Their fixes were almost always "you need to reconfigure your network" which simply wasn’t going to happen. The most chilling was "you need dedicated storage and should look at ours." There were instances of unprofessional behavior. Someone less technical, with a more standard network and insensitive to technicians pushing the upsell and being rude might be happy with Bluesound’s support. I was certainly not.

Started a significant system upgrade early last year and have replaced almost everything. First up was the addition of a QNAP NAS to serve up files (contrary to what the tech who tried to upsell me said, it did not resolve the issues with the Node2). Next, the Node2 was replaced by a SimAudio Moon MiND 2.

Did a head-to-head comparison between the two streamers, running both through the Opus’ DAC. The Mind 2 bested the Node2 by a significant margin. The MiND 2 delivered a decidedly cleaner and fuller sound. Just more of everything. Also did blind tests with friends and the result was the same. Their impressions of the MiND 2 echoed mine.

So far I am extremely happy with the Mind 2 and now have it paired with a Benchmark DAC3. My one disappointment with the MiND 2 is that its Android interface software was lacking (word is the Apple version is better). That was fixed through an upgrade to Roon, which is a fantastic product. So good that I bought a perpetual license.

Can’t comment on SimAudio or Roon’s technical support. Their products are so well thought out and designed that I haven’t had a single issue. Not one! The price for just the MiND is a little over your budget, but not by a lot. Happy to answer any questions you might have, too.

Good luck with the upgrade.