BlueSound Stinks(!), anyone?

I have found my node2i very stable. Also using an Ethernet cable to an Apple airport express. Compared to Oppo default streamer it is much more stable and a better overall interface (don’t know anything about Sonos). I did not do extensive sound quality comparisons because...
...The node DEFINITELY benefits from a good external DAC. The analog out on the node is not of the highest quality and would be a weak link in an otherwise medium to good quality system. I assume people with MEGA systems are not considering the node in their chain. 

I found the node 2i worked great.  I did use the ethernet connection and if you want the best sound that should be standard. 

An external DAC does help with sound quality as well. 

Overall very satisfied with bluesound. 

Fully empathise with the OP. I have owned and used Bluesound speakers and streamers over a 5 year period. Initially had Sonos (connect / play 1,5 etc) then replaced with Flex 2 / Node 2 before selling it all to move back to Sonos and then back to the later gen of Bluesound: Node 2i and Flex 2i. Overall I prefer the sound of Bluesound but recognise that the Sonos sound flavour feels to me a bit more dynamic. Bluesound has been very buggy when I owned the non 'I' versions, especially when I used it with Roon. They suffered a very well documented 'out of sync' bug that took about 18 months to resolve. The customer service experience was borderline traumatic with endless requests for the same logs, responses that had nothing to do with what was asked and 3-6 days wait time between each response. At the time Bluesound was denying the existence of the problem and was blaming Roon for everything. Roon customer support was more open in recognising there was a bug that was being worked on in collaboration with Bluesound. Bluesound denied this consistently. 
3 months of back and forth and I can safely say I felt like a Ping Pong ball... and not in a good way.

Fast forward to today, the 2i versions work a lot better but I agree with comments above regarding the flakiness with WiFi. What is more, I find that problems increase when using multiple blue sound units. Many users I see commenting in forums have only one Bluesound unit, usually the Node 2i or the Powernode 2i. My problems with WiFi increased significantly as moved from using a Node 2i alone to then adding 2 x Flex 2i speakers. Drop outs, speakers disappearing from the app and then coming back, volume slider freezing etc. Contacting customer support brought back the terrible experience: 5-7 days wait for each response to email, repeated requests of the same thing (despite providing the info asked), responses to questions I never asked (almost like mixing support tickets) and a by default denial of any recognition that there might be a bug. It almost felt like gaslighting and I just stopped engaging. I think that is what they hoped anyway.

While I love the sound of the Node 2i and Flex 2i with Roon especially, I would like to scale up to multiple speakers in the house. Having experienced the above over the years, no way I can take the risk. I may have to compromise and go back to Sonos for a more reliable experience (with necessary sound quality compromise).

I recognise this is just one person's experience but still... 

I realize this is an old thread but....I own three Nodes, have used them for about 5 years, in two different locations. Controlled mainly via IOS app and Windows app. All three get extensive use (pretty much constantly during the work day for my wife.) Have absolutely never had any issues at all with the app not connecting; I fully believe the OP of course but there’s gotta be something going on with his network or setup. I am not a fanboy of Bluesound and would make three criticisms: 1. No DSD. 2. it is needlessly picky about cover art and even when the cover art meets its requirements, sometimes it will not show, and 3. They use cheap caps in the power supply and 4 years service life is IME about all you’re gonna get, at least for versions pre-Node 2i. The latter of course being the most serious issue. but we have had zero problems getting them to work reliably.