Bluesound Node2 with outboard DAC

I think by connectivity I would say the OP means the ethernet connection?
Vault 2 is easy as it is hard wired ONLY, no choice for wireless and so in all honesty zero dropouts as long as you have a premium fast internet service.
The node 2 gives you option of both wired and wireless I think.
Where possible I run all my components on wired connections so as to minimize any chance of dropout. From my main hub upstairs I ran hard wires down to two smaller hubs downstairs so I could feed everything by hard wire in both the HT room and my stereo room but that might have been overkill...lol.
Some have reported occasional dropouts on the node using wireless but I would think again it would be more down to your router than the node unit.

mahler123, What I was meaning as far as connectivity I should have said connection / disconnection issues. My Oppo BDP105D on a regular basis while streaming disconnects from my tablet I use as the controller. So I have to reopen the app, go back into Tidal and go back to who I was listening to. It's a major pain in the rump. Otherwise I would probably just get a better dac like Benchmark, Bel Canto or Mytek. Mytek because it plays MQA. 
Can anyone support the difference and is it worth paying more for an MQA DAC to listen to MQA files vs FLAC and other Hi-Res files ? 

OP
I had huge issues with the OPPO app on my phone doing exactly the same and eventually gave up with it.
The OPPO is used purely for movies now and I use the Bluesound vault2 as my dedicated streamer, no connection issues from the Bluos app.

I'm also thinking of using an external DAC with node 2... and I'm also wondering if spending $1000 to $1200 going to get any tangible or even worthwhile boost in SQ.

aliskhan. 
I would have to say a resounding YES.
The weak link of the vault and node is the DAC, any half way decent DAC is an improvement. 1000 to 1200 gets you in the very good DAC market in todays equipment.