I'll add my impressions though I don't think others may like it. First off the features & inputs/outputs on this unit are phenomenal. Truly outstanding & covered all the bases. I don't fiddle with Bluetooth or Airplay so I have no dog in that fight.
I've used Dirac on a couple different devices as well as digital & analog Minidsp's. The room correction on the Ultra is not bad. Not Dirac level but definitely good enough if you have minor room or speaker issues. Compared to measurements I take with a Umik-1 and using REW they aren't identical to what the Ultra comes up with..but the corrections can make improvements without degradation if set up properly in the Ultra.
My only issue, which is a big one, is the overall sound quality. Maybe I shouldn't say it's an issue because of its price point..but I do think it sounds like a $300 plus a streamer. The bass is big but loose. Not very transparent. I think it sounds best using my RME dac due to it being very transparent, clear, detailed. Compared to my Primare Prisma NP5 streaming transport the WiiM is lacking in every category. The Prisma is twice the price though. And no streamer I've ever had has all the features the Ultra has. I do get a pretty decent sized soundstage with the Ultra though.
So I guess maybe I'm being too critical but I think it sounds like it's price. Which is fine but the online reviews were saying otherwise. Things like how great it sounded in $10k to $50k systems. It's a good device, not "audiophile" quality lol.
The streamers I have personally owned in the budget-ish category over the last few years are the Mini, the Node, Zen stream, B&W Formation, Cambridge CXN2, MXN10, Arcam SA30, the Prisma, & a cheap Arylic. The Zen & Prisma being the best of the bunch with upgraded PS. They are also the only ones that were "transports" only.
I want to reiterate that I'm not really knocking the Ultra. This thing can literally be a great preamp obviously. Sub output, EQ/DSP, analog input, decent internal dac, volume control, etc. etc. Its remarkable what they have put into this thing. And I was surprised at its overall size..& I actually like the display screen. Just wish it sounded a little better. A little more resolution & detail. With my tube amps it's not too bad. Something like my Hypex Nilai and it's pretty sibilant. Which is usually the sign of the source having moderate power supply noise.
App has been great. I mostly use Quboz but have Amazon music as well.
That's my 2 week impressions.