iOS wired thru decent DAC vs BS Node 2i alone

Put the latest update on a USB stick and try rewriting the firmware manually if you haven't already. 

Wired - trapped like a rat.

Wireless - inferior

I have not tested against a BS node.   But I have tested an iPAD streaming from the Qobuz app hard wired to my DAC via USB.  I was surprised how good it sounded streaming 24/96.  Maybe a little bit flatter sound stage than my streamer but still purdy good.  Cool thing is you can down load the files local to the iPAD and stream them from there with Qobuz and I expect other high end streaming services. 

The Node is very pleasing and convenient as an all-in-one, but a DAC like the one you mention above and a good USB cable will outperform it. The 2i uses a Burr-Brown chip and does not provide much quality with regards to noise reduction or quality analog stage, and its resolution as a result is lacking and if you do compare it, the Node 2i will sound more congested, less transparent. That said, the Topping D90SE is very revealing, though can be fatiguing at times depending on the rest of the chain. The Denafrips Ares is somewhere in between.

In full disclosure, I owned a house full of Bluesound, and I graduated to the NAD M50.2 dedicated streamer because it was still on BluOS. But it wasn’t until I moved to Aurender when I started really hearing what a great digital streamer can truly do.