How much would I lose going to a Bluesound Node 2i

The OP poses an interesting question.  I won’t be able to fully answer it but perhaps he may benefit from my experience.
  I have the Node2 and the Vault2.  The weak link in both is the DAC and for both I use external DACs.  None of my DACs do MQA.  When Bluesound added MQA I tried a few recordings via a 10 day Tidal membership.  I limited myself to recordings that were already in my collection.  My DACs are the Bryston DAC 3 and Mytek Manhatten I.  For MQA I used the DAC in the Vault2.
   The MQA albums that listened to were compared both to CDs played on an Oppo transport with SPDIF out into my DACs and CDs that had been burned into the Vault2.  I preferred listening non MQA
with either the Oppo or the Vault2 as a transport.
  When I compared ripped CDs from the Vault2 via the Internal DAC compared with MQA from Tidal via the Vault2 the results were inconsistent.  Sometimes it was a marginal improvement, but not always, and in some cases the plain vanilla from the Vault2 was better.  In every case I preferred my non MQA DACs by a wide margin.
  The OP seems more taken with MQA than I was.  My advice would be to stop worrying about the links in the chain if the end result sounds good.  Perhaps try the Node 2i (which is supposed to have a better DAC than my current Bluesound components) but hang on to the Aries (is it upgradeable via firmware updates) in case they embrace MQA.

+1 Mahler.
I think MQA is just another gimmick to make us buy an unnecessary product. A well recorded high rez recording holds up against MQA.
As others have said the Node DAC is good, but at least you can bypass it to a DAC of you own choice.
I use an Ayre Codex and have nothing bad to say about this combination.
B 

I have the Node2i and when I bought a Benchmark DAC3B  to use with my old Onkyo CDP I also connected the Node2i  to compare and to me it depended on the recording some I thought were  a little better through the Node2i  some the Benchmark   which does a partial unfold of MQA to 24/96 but it was really hard to tell. I also thought the same recording in CD sounded better on either so Someone with better equipment  and ears than me might hear a big difference  I never did. To the OP all I can say is you will need try for yourself. 

Obviously it's all subjective, but I had the Node 2i playing coax out to my Rotel 1572 and I thought the Rotel sounded a bit better even with MQA files.

Now, I have the Metrum Ambre with Metrum Onyx and well...that is an obvious step up in everything. However, I did have the Ambre hooked up to my Rotel 1572 for a short time and the difference was quite noticeable.

I'm thinking the higher up in performance you get with DAC's the less you will be able to tell difference with MQA. I do agree that some MQA tracks sound better than the same track non MQA. I'm still on the fence on how I feel about it. Now, i just let the Ambre and Roon do the MQA unfold. I realize I may not be getting the full monty, but I'm not worried about it. 

I maybe in the minority here but I do believe MQA makes a significant SQ difference at least to my ears in my system.
I have two methods of streaming MQA right now and I find both to be superior to non MQA albums from Tidal.

Bluesound Vault 2 via SPDIF to Mytek Brooklyn letting the Brooklyn handle the MQA. You have to hear a 24/192 recording to believe it!

Auralic Aries Mini via USB to Mytel Brooklyn again letting the Brooklyn handle the MQA. Even further up the food chain imho.

But back to the OP question.

I still feel that the internal DAC in the Bluesound products is inferior to an external high quality DAC ( as it should be considering the price difference!) but the Node 2i is supposed to be improved so you may very well be satisfied with it. At least you have the option of trying its DAC or output to a higher quality MQA capable DAC down the road.