Looking to use the Bluesound Vault 2i High-Res 2TB Network Hard Drive CD Ripper/Streamer

You insert the CD into the vault and it will copy the CD to the internal drive in Flac format or Wav format whichever you choose. Yes, you use the app for playback. 

In addition to what djones51 suggested, hardwired Vault2i to your router using a good quality Ethernet cable with RJ45 connectors. Next step would be to subscribe to Tidal or Qobuz for high resolution streaming. They both offer 30 days trial.

To answer your question, your CD rips on Vault 2 should sound decent, lot of it depends on RCA cable and AV processor you’re using. You would connect Vault 2 (RCA outs) to your processor CD Input not output with a RCA interconnect cable. Mind you, folks here have achieved better sound by connecting Vault or Node 2 with an external DAC.

I own a Vault 2 and use it mainly for CD rips and as a back up to my Aurender streamer.

Harley writes that the rips sound better in his Complete Guide...
They are at least as good and a lot more convenient. There's that.
It's easier to rip on the computer if you are picky about tags like I am.

OP
lots of threads about Bluesound in the Digital and PC forums.
fwiw, I will disagree with djones and say that using my CD player as a transport into my DAC sounds slightly better than playing the ripped CD on the Vault2, but it isn’t a night and day difference.  Another factor is using the Bluesound app to find your music; as with all streaming apps you may love it or hate it, and it is a significant part of the experience.

I have the Vault 2i and love it,  streaming has changed the way I listen to music.   Sure, I put all of my discs in it, but mainly use it to stream Qobuz.  Many times I will find myself playing the Hi Res version of CDs I already own