I've got a Bluesound Node 2 for a year and am quite happy with it. However, I'm not a very picky listener so may not be able to answer all your questions fully.
I don't use Wifi, only hardwired Ethernet. Only at installation I needed Wifi, and then it did work okay as far as I could tell.
There have been regular software updates to both the control apps (on OSX (computer), iOS (iPad) and Android (mobile phone)), which on occasion have been major changes, but on the whole I think they do a good job. There is a heated debate on the Bluesound forums regarding a past change for adding new tracks (which worked counterintuitively). This has since been changed/improved in a way that resembles how other programs work (for example Audirvana). I think the debate was somewhat overblown, the important thing to me is that there is an active development team working on the software.
The app suits me fine. I have noted some changes in lay-out and so on, but nothing that threw me. Occasionally I lose connection which may be due to my Wifi connection; this seems to occur more often with my phone than from the computer app.
The firmware is also updated regularly. The Node warns that there is an update available and asks whether you like to update. The whole process works automatically (takes at most some 5-10 minutes) and has never failed me. I can't remember that there were major changes.
One thing I don't like is that it always scans the USB-drive (if you have attached one) at start-up, which takes a while depending on the size of the library on the drive. Hence you can't use it instead of a NAS. But frankly I nowadays mostly use streaming (Tidal and Qobuz).
Sound quality is as far as I can tell okay/good. This is difficult for me to describe as I have no experience with real high-end DACs, and furthermore am inclined to believe that the differences between reasonable/good quality DACs are slight anyway. I have played around with various configurations. Using the digital out to the DAC of my Quad Vena is very similar to the Node's DAC, the Vena possibly being just a touch warmer. Using the digital input of the Node to use as a DAC with CD's from a DVD player (used as transport) works fine as well.
I find the Bluesound a nice little streamer, probably quite similar to competing products. To me the benefits are the small form factor and the regular updates for app and firmware, while it does allow streaming of Qobuz and Tidal. I would have liked to attach a hard drive instead of using a NAS, but that doesn't seem feasible.
With respect to MQA: I have tried downloaded MQA files from 2L, and Master quality from Tidal. My vague impression is that the sound has a sharper, more refined quality. Presently I have attached cheap Cambridge Minx speakers and sub to the Quad Vena, and with MQA it seemed as if I suddenly had upgraded my speakers to one class higher. Instruments seem to have more presence, if that makes sense. But of course this is not a controlled double blind test.